cas 288071-87-4, 4,7-Bis(2-bromo-5-thienyl)-2,1,3-benzothiadiazole

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Synthesis and properties of new low band gap semiconducting polymers
Low band gap organic semiconducting polymers were prepared as p-type donors for organic photovoltaic devices. A novel dibrominated monomer composed of phenothiazine, thiophene, and benzothiadiazole (DPDTBT) was synthesized as a low band gap core block. DP
Kim, Ji-Hoon,Kang, Jun,Mi, Dongbo,Xu, Fei,Jin, Sung-Ho,Chun, Ho-Hwan,Hwang, Do-Hoon
p. 5187 - 5191
(2014)
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Solution-processable crystalline platinum-acetylide oligomers with broadband absorption for photovoltaic cells
A series of solution-processable and crystalline platinum-acetylide oligomers containing a thienyl-benzothiadiazole-thienyl core and oligothiophene alkynyl ligands are synthesized and characterized. X-ray crystallography analysis indicates a two-dimensional arrangement of oligomers through CH- interactions in single crystals. These oligomers show two intense and broad absorption bands in the visible spectral region, with the short-wavelength absorption band being strongly dependent on the oligothiophene length. In neat films, all the oligomers form large crystalline domains of several hundred nanometers in size upon thermal treatment and exhibit space-charge limited current (SCLC) mobilities on the order of 10-5-10-4 cm2-V-1-s-1. The photovoltaic properties of these oligomers were evaluated by fabricating bulk heterojunction devices with fullerene derivatives (PC61BM and PC71BM) and some of these devices showed high-power conversion efficiencies (PCEs) of up to 3% and a peak external quantum efficiency (EQE) to 50% under AM 1.5 simulated solar illumination. The present work suggests that well-defined platinum oligomers with desirable light-absorbing and self-assembly properties have potential for solution-processed organic photovoltaics.
Zhao, Xiaoyong,Piliego, Claudia,Kim, Bongsoo,Poulsen, Daniel A.,Ma, Biwu,Unruh, David A.,Frechet, Jean M. J.
p. 2325 - 2332
(2010)
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Synthesis and electrostatic Nano-Assembly of water-soluble Polybenzothiadiazole derivatives with long-wavelength emission in the solid states
We have synthesized APBT and APTBT containing benzothiadiazole units by Suzuki cross-coupling reaction with good yield. The polymers showed blue emission colors in aqueous solutions, while long wavelength shift was observed in the solid state due to facilitated exciton migration. APBT and APTBT are water-soluble and highly-fluorescent conjugated polymers with negatively charged sulfonate side chains and thus they can be electrostatically assembled with oppositely charged polyelectrolyte such as cationic polymer, poly(dimethyldiallylammonium chloride) (PDAC) via layerby- layer (LbL) deposition technique on a glass slide. According to the increased the number of bilayer, we found that the assembled film exhibited larger enhancement of the long wavelength emission relative to the blue emission, due to the increased excition migration. Copyright
Lee, Jung Hyo,Kim, Dai Geun,Jang, Geun Seok,Lyoo, Won Seok,Park, Won Ho,Lee, Minjung,Lee, Taek Seung
p. 6977 - 6980
(2010)
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Nonlinear Optical Studies of Conjugated Organic Dyes for Optical Limiting Applications
D-π-A conjugated organic dyes made of different donor/acceptor moieties namely Hexylcarbazole (HC), 4,7- Dithiophene-2-yl) benzo[c][1,2,5]thiadiazole (DTBT) and Poly-4-(5-(9-Hexyl-9H-carbazol-2-yl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (PCTB) were prepared by coupling reactions. FTIR, NMR, and mass spectrometry were used to determine the molecular structure of synthesized compounds. Both HC and DTBT show a wide optical transmittance window (400-600 nm) with absorption maxima in the UV region. However, PCTB shows an altered band structure with a broad absorption in the visible domain (448 nm). Density functional theory (DFT) calculations expose that the bandgap between HOMO and LUMO decreases as the conjugation extends, and redshift occurs in UV-Vis absorption spectra. The emission spectrum of PCBT shows strong emission maxima at 541 nm with the corresponding large Stokes shift 3837 cm?1 due to its enhanced charge transfer property in the excited state. Nonlinear optical absorption was studied by open-aperture Z-scan technique using Nd:YAG laser (532 nm, 10 Hz, 9 ns). Here HC, DTBT exhibit a genuine two-photon absorption (TPA) process while PCTB possesses sequential TPA involving excited-state absorption. All dyes exhibit energy-absorbing optical limiting behaviour ascribed due to the two-photon absorption process. Among the investigated dyes, PCTB polymer shows a higher TPA coefficient (1.22 × 10?10 m/W) and a lower onset optical limiting threshold (1.06 × 1012 W/m2). Thus, the tunability of band structure and nonlinearity with a change in the molecular arrangement was successfully demonstrated in thiophene-benzothiadiazole-based organic dyes.
Anandan, S.,Girisun, T. C. Sabari,Habeeba, AA Ummu,Saravanan, M.
(2021/05/17)

An ultra-highly sensitive and selective self-enhanced AIECL sensor for public security early warning in a nuclear emergencyviaa co-reactive group poisoning mechanism
The worldwide application of nuclear power has created the potential risk of a nuclear accident, which has been a challenge to public security. In nuclear leakages, I2radioisotopes would cause rapid, global pollution. Therefore, highly sensitive and selective I2sensors exhibit their significance in nuclear accident early warnings and treatments. Herein, a conjugated polymer was developed for I2vapor monitoring with an ultra-low limit of detection (LOD). This polymer, modified with a tertiary amine as a co-reactive group, exhibits aggregation-induced electrochemiluminescence (AIECL) and self-enhanced ECL behaviors. It is noteworthy that the tertiary amine also acts as I2vapor capturing and sensing groups to give a LOD of 0.13 ppt. Excellent selectivity was obtained in various interfering atmospheres. A new mechanism was discovered for designing vapor sensors, which is summarized as co-reactive group poisoning (CGP). To meet the high efficiency requirement of nuclear emergency monitoring, an I2sensor modified screen printed carbon electrode was used due to its low cost, lack of need for pretreatment and suitability for mass production. A matching upwardly photosensitive ECL dark box was further designed. This study reports ECL vapor monitoring for the first time and provides a novel strategy for early warning of a nuclear emergency, suggesting its significance in environmental and public security fields.
Hua, Daoben,Liu, Peng,Pan, Jian-Bin,Wang, Ziyu,Wu, Xinqi,Xu, Jing-Juan,Xu, Meiyun,Zhang, Nan
supporting information
p. 12584 - 12592
(2021/06/14)

Synthesis of donor-acceptor-type conjugated polymer dots as organic photocatalysts for dye degradation and hydrogen evolution
Conjugated polymers (CPs) having various donor-acceptor units in the main chain were synthesized via Suzuki coupling reaction for an organic photocatalyst that can generate reactive oxygen species (ROS) for dye degradation and H2 evolution unde
Gwon, Yougjin,Jo, Seonyoung,Lee, Hyun-Jun,Lee, Taek Seung,Park, Soo Young
(2021/07/14)

Effect of thiophene/furan substitution on organic field effect transistor properties of arylthiadiazole based organic semiconductors
Four donor-acceptor (D-A) type organic semiconductors, consisting of 5-hexylthiophene with thiophene/furan flanked benzothiadiazole/naphthothiadiazole, were investigated for organic field effect transistor (OFET) application. Despite being an analogue of thiophene, furan has received less attention in organic electronics due to its dissimilar properties to thiophene and instability in photochemical oxidation. Nevertheless, this study determines that furan could display comparable charge transport properties to its analogue. The extension of the electron-accepting thiadiazole core with the benzo group and different heteroatom flanking groups were investigated to show that the performance of OFETs is dependent on the molecular orbital, geometry, and packing. Bottom-gate bottom-contact device configuration was used to study the OFET transport properties of all the molecules. We successfully proved that a furan unit is a promising building block with a mobility (μmax) of 0.0122 cm2 V-1 s-1 for devices employing furan-substituted benzothiadiazole as the channel layer.
Pachariyangkun, Anna,Suda, Masayuki,Hadsadee, Sarinya,Jungsuttiwong, Siriporn,Nalaoh, Phattananawee,Pattanasattayavong, Pichaya,Sudyoadsuk, Taweesak,Yamamoto, Hiroshi M.,Promarak, Vinich
supporting information
p. 17297 - 17306
(2021/01/05)

Effect of end group functionalisation of small molecules featuring the fluorene-thiophene-benzothiadiazole motif as emitters in solution-processed red and orange organic light-emitting diodes
A series of red fluorescent materials (compounds 1-4), which each contain the symmetric fluorene-thiophene-BT-thiophene-fluorene core, is presented along with their performance in solution-processed OLED devices. Extending the molecular conjugation throug
Fell, Valentin H. K.,Findlay, Neil J.,Breig, Benjamin,Forbes, Clarissa,Inigo, Anto R.,Cameron, Joseph,Kanibolotsky, Alexander L.,Skabara, Peter J.
p. 3934 - 3944
(2019/04/30)

Efficient aggregated luminescent material and preparation method thereof
The invention relates to an efficient aggregated luminescent material and a preparation method thereof. The preparation method comprises the following steps: (1) Stille coupling of thienyl; (2) N-bromosuccinimide (NBS) bromination; (3) [2.2] paracycloalkane cross-coupling. The synthetic process of the luminescent material provided by the invention is simple in conditions and relatively low in preparation cost; at the same time, the luminescent material has relatively good aggregated luminescence property and optical stability, and can realize thorough application researches in stimulated emission depletion (STED) ultra-high resolution imaging.
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Paragraph 0022; 0028-0031; 0036; 0039; 0041; 0044

(2019/10/23)

Phenolic Bis-styrylbenzo[ c]-1,2,5-thiadiazoles as Probes for Fluorescence Microscopy Mapping of Aβ Plaque Heterogeneity
A fluorescent bis-styryl-benzothiadiazole (BTD) with carboxylic acid functional groups (X-34/Congo red analogue) showed lower binding affinity toward Aβ1-42 and Aβ1-40 fibrils than its neutral analogue. Hence, variable patterns of neutral OH-substituted bis-styryl-BTDs were generated. All bis-styryl-BTDs showed higher binding affinity to Aβ1-42 fibrils than to Aβ1-40 fibrils. The para-OH on the phenyl rings was beneficial for binding affinity while a meta-OH decreased the affinity. Differential staining of transgenic mouse Aβ amyloid plaque cores compared to peripheral coronas using neutral compared to anionic bis-styryl ligands indicate differential recognition of amyloid polymorphs. Hyperspectral imaging of transgenic mouse Aβ plaque stained with uncharged para-hydroxyl substituted bis-styryl-BTD implicated differences in binding site polarity of polymorphic amyloid plaque. Most properties of the corresponding bis-styryl-BTD were retained with a rigid alkyne linker rendering a probe insensitive to cis-trans isomerization. These new BTD-based ligands are promising probes for spectral imaging of different Aβ fibril polymorphs.
Zhang, Jun,Konsmo, Audun,Sandberg, Alexander,Wu, Xiongyu,Nystr?m, Sofie,Obermüller, Ulrike,Wegenast-Braun, Bettina M.,Konradsson, Peter,Lindgren, Mikael,Hammarstr?m, Per
p. 2038 - 2048
(2019/02/26)

Organic dyes end-capped with perfluorophenyl anchors: Synthesis, electrochemical properties and assessment of sensitization capacity of titania photoanodes
In the present work, organic sensitizers are synthesized and attached on TiO2 photoanodes via Ti-O-C bonds. All sensitizers, designed for this purpose are symmetrical and have two perfluorophenyl end groups, which can lead to stable non-hydroly
Giannopoulos, Panagiotis,Raptis, Dimitrios,Theodosiou, Krystallia,Andreopoulou, Aikaterini K.,Anastasopoulos, Charalampos,Dokouzis, Alexandros,Leftheriotis, George,Lianos, Panagiotis,Kallitsis, Joannis K.
p. 167 - 179
(2017/09/15)

Access to small molecule semiconductors: Via C-H activation for photovoltaic applications
The first methodology of ruthenium carboxylate-catalysed single step oxidative cross coupling that challenges the conventional Stille and Suzuki coupling reactions, affording BT and MFBT derivatives in the absence of protecting groups, was developed. Both mono and bi-arylated derivatives are formed in moderate to high yields (30-75%). Innately high selectivity, low catalyst loading and lack of formation of regio-isomers ensure the large-scale synthesis of various photonic and electronic materials employing this method.
Shome, Sanchari,Singh, Surya Prakhash
supporting information
p. 7322 - 7325
(2018/07/06)

Synthesis and photovoltaic studies on novel fluorene based cross-conjugated donor-acceptor type polymers
Direct arylation polymerization (DAP) is emerging as a promising green, cheap, simple, and efficient environment friendly method for synthesizing conjugated polymers without involving any organometallic reagent. We report fluorene based novel cross-conjugated alternate and random copolymers for polymer solar cells (PSCs), which were synthesized by DAP and/or Yamamoto polymerization under appropriate reaction conditions to obtain high molecular weight. These cross-conjugated polymers possess absorption maxima in the range of 490–520 nm and have narrow band gap (1.7–2.05 eV) which is suitable for bulk heterojuntion (BHJ) type organic solar cells. Among the synthesized polymers, the highest number average molecular weight (Mn) i.e. 43.1 kg mol?1 was obtained for polymer P2b (poly((9H-fluoren-9-ylidene)methylene)bis((2-ethylhexyl)sulfane)-alt-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)), and so good polymeric films were formed for P2b. Thus, BHJ films were prepared for P2b for device performance studies and the morphology of these films was studied by atomic force microscopy (AFM). Polymer P2b was blended with the fullerene derivative [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) in different ratios and under the illumination of solar simulator with Air Mass global (AM 1.5G) irradiated at 100 mW cm?2. Power conversion efficiency (PCE) of 1.4% has been achieved for BHJs in ratio of 1:2 of P2b: PC71BM in simply processed devices. This result indicates that cross-conjugated polymers can be tapped as potential donors for BHJs as the PCE obtained is the highest among this type of cross-conjugated polymers.
Sharma, Bhavna,Alam, Firoz,Dutta, Viresh,Jacob, Josemon
p. 42 - 50
(2016/12/02)

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications
A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at -5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3.
Viswanathan, Vinila N.,Rao, Arun D.,Pandey, Upendra K.,Kesavan, Arul Varman,Ramamurthy, Praveen C.
supporting information
p. 863 - 873
(2017/06/21)

A comparative study of the effect of fluorine substitution on the photovoltaic performance of benzothiadiazole-based copolymers
Two conjugated alternating copolymers to be used as the donor materials of the active layers in polymer solar cells have been designed and synthesized via a Stille coupling reaction. The alternating structure consisted of 4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene (BDT) as the donor unit and benzo[c][1,2,5]thiadiazole (BT) or fluorinated benzo[c][1,2,5]thiadiazole (FBT) as the acceptor unit, along with a thiophene group as the π-bridge between the donor and acceptor units. Since the donor units have attached alkoxy pendant chains, both polymers were soluble in common organic solvents. UV-vis spectra of both copolymers exhibited broad absorption bands in the range of 325-900 and 380-900 nm, respectively, and corresponding low band gaps of 1.82 and 1.80 eV. After fluorination of the BT unit, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the polymer were lowered and estimated to be -5.51 and -3.71 eV, respectively. It was found that substitution of an F atom into the BT units facilitated the intramolecular charge transfer. In comparison with the nonfluorinated polymer, the photovoltaic performance of the fluorinated polymer was significantly improved due to the enhanced Jsc and Voc. Based on the ITO/PEDOT:PSS/polymer:PC61BM/LiF/Al device structure, the optimal device efficiency was obtained from a device with a blend of PBDTFBT and PC61BM at a weight ratio of 1:1. For this blend ratio, the values of Jsc and power conversion efficiency (PCE) obtained at room temperature are 7.98 mA cm-2 and 3.62%, respectively, under the illumination of AM 1.5 (100 mW cm-2).
Wang, Tzong-Liu,Yang, Chien-Hsin,Chuang, Yao-Yuan
p. 47676 - 47686
(2016/06/06)

Vacuum-depositable thiophene- and benzothiadiazole-based donor materials for organic solar cells
Three (D-A-D)-type electron donor materials, containing 2,1,3-benzothiadiazole as the electron-withdrawing core, and benzothiophene, naphthalene, and thiophene as electron-donating terminal groups, were synthesized for vacuum-depositable small-molecule organic solar cells. The donor material containing thiophene as the terminal group, DT, shows a maximum power conversion efficiency of 4.13%, a short-circuit current density of 9.89 mA cm-2, an open-circuit voltage of 0.86 V, and a fill factor of 0.48, in a bulk heterojunction solar cell with a blend ratio of DT:C70 = 1 : 4 under simulated AM 1.5 solar irradiation at 100 mW cm-2.
Jeon, Yongjun,Kim, Tae-Min,Kim, Jang-Joo,Hong, Jong-In
p. 9591 - 9595
(2015/12/01)

Thiophene-fused benzothiadiazole: A strong electron-acceptor unit to build D-A copolymer for highly efficient polymer solar cells
A novel strong electron-acceptor, thieno[2,3-f]-2,1,3-benzothiadiazole-6- carboxylate (BTT), was first designed and synthesized. By introducing two thienyl groups into BTT and then copolymerizing with thienyl group substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT) unit, a low band gap D-A copolymer (PBTT-TBDTT) was obtained. Compared with its polymer analogue (PBT-TBDTT) with benzothiadiazole (BT) as an acceptor, PBTT-TBDTT exhibits stronger intramolecular charge transfer. Thus, it shows much broader absorption covering almost the whole visible light region (in the range of 300-850 nm) and narrower optical band gap around 1.45 eV with a large IP (ionization potential) at 5.35 eV. The maximum efficiency of PBTT-TBDTT based device reaches 6.07% which is much higher than that of PBT-TBDTT (3.24%), indicating that BTT unit is a promising electron-acceptor moiety to construct low band gap D-A copolymers for PSCs with high photovoltaic performances.
Zhou, Pengcheng,Zhang, Zhi-Guo,Li, Yongfang,Chen, Xingguo,Qin, Jingui
p. 3495 - 3501
(2014/06/24)

New conjugated alternating benzodithiophene-containing copolymers with different acceptor units: Synthesis and photovoltaic application
Two new alternating low band gap D-A copolymers with different acceptor structures of 4,8-bis-(5-bromothiophene-2-yl)-benzo[1,2,5]thiadiazole (P1) and 4,8-dithiophene-2-yl-benzo[1,2-c;4,5-c′]-bis-[1,2,5]thiadiazole (P2) and a common BDT donor segment have been synthesized under Stille reaction conditions and characterized. The polymers showed good solubility, broad absorption bands and optical band gaps of 1.62 eV and 1.16 eV for P1 and P2, respectively. Bulk heterojunction (BHJ) polymer solar cells based on P1 and P2 as electron donors and fullerene derivatives (PC60BM and PC70BM) as acceptor were fabricated and their photovoltaic response was investigated. The overall power conversion efficieny (PCE) achieved for BHJ solar cells based on P1:PC60BM, P2:PC60BM, P1:PC70BM and P2:PC 70BM blends cast from THF solvent is about 2.17%, 0.80%, 3.45% and 1.19%, respectively. The higher PCE for the device based on P1 has been attributed to the high value of hole mobility for P1 as compared to P2 and a larger driving force i.e. LUMO-LUMO offset, for photo-induced charge transfer for P1:PCBM BHJ active layer. The PCE has been further increased up to 5.30% and 1.58% for P1:PC70BM and P2:PC70BM blends cast from DIO/THF solvent, which is attributed to the improved crystallinity and a more balanced charge transport in the device. The Royal Society of Chemistry.
Keshtov,Marochkin,Kochurov,Khokhlov,Koukaras,Sharma
p. 155 - 171
(2014/01/06)

Small band gap D-π-A-π-D benzothiadiazole derivatives with low-lying HOMO levels as potential donors for applications in organic photovoltaics: A combined experimental and theoretical investigation
In an attempt to develop small organic molecules with potential applications as donors in organic photovoltaic (OPV) devices, we have synthesized and characterized four novel benzothiadiazole (A) core structured D-π-A-π-D dyes featuring carbazole and benzocarbazole as donors (D) and fluorene and thiophene as spacers (π). The effects of the π-spacer units and variations in donor strength on the photophysical, electrochemical and thermal properties of the molecules have been investigated in detail. The replacement of fluorene by thiophene as a π-spacer promotes planarity, resulting in a larger bathochromic absorption shift, enhanced emission profiles and an enhanced intramolecular charge transfer (ICT) transition. The introduction of the benzocarbazole unit creates a low-lying HOMO level, as inferred from cyclic voltammetry studies. All the dyes exhibit remarkable thermal robustness. Theoretical calculations have been carried out to understand the structure-property relationships of the synthesized materials. The results obtained from the characterization methods reveal that the dyes with thiophene π-spacers show better optoelectronic properties compared to their fluorene counterparts. Solution-processable bulk-heterojunction devices with a structure of ITO/PEDOT:PSS (38 nm)/active layer/Ca (20 nm)/Al (100 nm) were fabricated using the materials investigated in this study as donors and (6,6)-phenyl C 61-butyric acid methyl ester (PC61BM) as an acceptor. A power conversion efficiency of 1.62% for the molecule with thiophene as a spacer and carbazole as donor/PC61BM was achieved for the preliminary photovoltaic devices under simulated AM 1.5 illumination (100 mW cm -2).
Paramasivam, Mahalingavelar,Gupta, Akhil,Raynor, Aaron M.,Bhosale, Sheshanth V.,Bhanuprakash,Jayathirtha Rao
p. 35318 - 35331
(2014/11/12)

A versatile approach to organic photovoltaics evaluation using white light pulse and microwave conductivity
State-of-the-art low band gap conjugated polymers have been investigated for application in organic photovoltaic cells (OPVs) to achieve efficient conversion of the wide spectrum of sunlight into electricity. A remarkable improvement in power conversion efficiency (PCE) has been achieved through the use of innovative materials and device structures. However, a reliable technique for the rapid screening of the materials and processes is a prerequisite toward faster development in this area. Here we report the realization of such a versatile evaluation technique for bulk heterojunction OPVs by the combination of time-resolved microwave conductivity (TRMC) and submicrosecond white light pulse from a Xe-flash lamp. Xe-flash TRMC allows examination of the OPV active layer without requiring fabrication of the actual device. The transient photoconductivity maxima, involving information on generation efficiency, mobility, and lifetime of charge carriers in four well-known low band gap polymers blended with phenyl-C61-butyric acid methyl ester (PCBM), were confirmed to universally correlate with the PCE divided by the open circuit voltage (PCE/Voc), offering a facile way to predict photovoltaic performance without device fabrication.
Saeki, Akinori,Yoshikawa, Saya,Tsuji, Masashi,Koizumi, Yoshiko,Ide, Marina,Vijayakumar, Chakkooth,Seki, Shu
supporting information
p. 19035 - 19042
(2013/01/15)

Introduction of perylene units for enhanced interchain interaction in conjugated polymers for organic photovoltaic devices
A series of semiconducting copolymers, poly[2,7-(9,9′- dioctylfluorene)-alt-5,5′-(4′,7′-di-2-thienyl-2′, 1′,3′-benzothiadiazole)] (PFDTBT), poly[2,2′-(9,9-dioctyl-9H- fluorene-2,7-diyl)dithiophene-alt-5,5′-(4′,7′-di-2-thienyl- 2′,1′,3′-benzothiadiazole)] (PFD2TBT), and their ter-polymers containing perylene units were synthesized using Suzuki coupling polymerization. The perylene units were introduced to improve the charge-transport ability by enhancing the π-π interaction between polymer chains. The resulting polymers were characterized by 1H NMR, elemental analysis, DSC, and TGA. The synthesized polymers were soluble in common organic solvents, and formed smooth and uniform spin-coated thin films. All of the polymers studied were found to exhibit good thermal stability, losing less than 5% of their weight upon heating to approximately 350 °C. Perylene- containing polymers showed higher field-effect mobilities than the corresponding PFDTBT or PFD2TBT polymers because of the enhanced π-π interaction between polymer chains upon the introduction of perylene units. Bulk heterojunction solar cells were fabricated with configuration of ITO/PEDOT:PSS/polymer:PC71BM/ TiOx/Al. The devices using the perylene-containing polymers showed higher short-circuit currents, and fill factors than the corresponding PFDTBT or PFD2TBT devices. One of the fabricated devices using a perylene-containing copolymer showed a maximum power conversion efficiency of 3.16%, with a short circuit current density of 9.61 mA/cm2, open circuit voltage of 0.81 V, and fill factor of 41%.
Kim, Ji-Hoon,Kim, Hee Un,Mi, Dongbo,Jin, Sung-Ho,Shin, Won Suk,Yoon, Sung Cheol,Kang, In-Nam,Hwang, Do-Hoon
experimental part
p. 2367 - 2376
(2012/06/29)

Incorporation of pyrene units to improve hole mobility in conjugated polymers for organic solar cells
Solution-processable semiconducting copolymers, poly[N-9′- heptadecanyl-2,7-carbazole-alt-5,5′-(4′,7′-di-2-thienyl- 2′,1′,3′-benzothiadiazole)] (PCDTBT) and poly[4,8-bis(2- ethylhexyl-2-thenyl)-benzo[1,2-b:4,5-b′]dithiophene-alt-5, 5′-(4′,7′-di-2-thienyl-2′,1′,3′- benzothiadiazole)] (PBDTDTBT), and their pyrene-containing terpolymers were synthesized using Suzuki or Stille coupling. Pyrene units were introduced to improve the charge-transporting abilities of the polymers. The resulting polymers were found to be soluble in common organic solvents and formed smooth and uniform spin-coated thin films. They also exhibited good thermal stability and lost 71BM/Ca/Al configuration fabricated using the pyrene-containing polymers had higher power conversion efficiencies than those using the corresponding parent polymers.
Kim, Ji-Hoon,Kim, Hee Un,Kang, In-Nam,Lee, Sang Kyu,Moon, Sang-Jin,Shin, Won Suk,Hwang, Do-Hoon
p. 8628 - 8638
(2013/01/15)

Photovoltaic devices using semiconducting polymers containing head-to-tail-structured bithiophene, pyrene, and benzothiadiazole derivatives
An alternating copolymer composed of heal-to-tail-structured 3,4'-dihexyl-2,2'-bithiophene (DHBT) and pyrene units [poly(DHBT-alt-PYR)] was synthesized using a Stille coupling reaction for use in photovoltaic devices as a p-type donor. For the reduction of the bandgap energy of poly(DHBT-alt-PYR), 4,7-bis(3'-hexyl-2,2'-bithiophen-5-yl)benzo[c][1,2,5]thiadiazole (BHBTBT) units were introduced into the polymer. Poly(DHBT-co-PYR-co-BHBTBT)s were synthesized using the same polymerization reaction. The synthesized polymers were soluble in common organic solvents and formed smooth thin films after spin casting. The optical bandgap energies of the polymers were obtained from the onset absorption wavelengths. The measured optical bandgap energy of poly(DHBT-alt-PYR) was 2.47 eV. As the BHBTBT content in the ter-polymers increased, the optical bandgap energies of the resulting polymers decreased. The bandgap energies of poly(50DHBT-co-40PYR-co-10BHBTBT) and poly(50DHBT-co-20PYR-co-30BHBTBT) were 1.84 and 1.73 eV, respectively. Photovoltaic devices were fabricated with a typical sandwich structure of ITO/PEDOT:PSS/active layer/LiF/Al using the polymers as electron donors and [6,6]-phenyl C71-butyric acid methyl ester as the electron acceptor. The device using poly(50DHBT-co-20PYR-co- 30BHBTBT) showed the best performance among the fabricated devices, with an open-circuit voltage, short-circuit current, fill factor, and maximum power conversion efficiency of 0.68 V, 5.54 mA/cm2, 0.35, and 1.31%, respectively.
Kim, Ji-Hoon,Lee, Sunyoung,Kang, In-Nam,Park, Moo-Jin,Hwang, Do-Hoon
scheme or table
p. 3415 - 3424
(2012/08/29)

Easily attainable phenothiazine-based polymers for polymer solar cells: Advantage of insertion of S,S-dioxides into its polymer for inverted structure solar cells
Two donor-(D-) acceptor (A) type polymers based on a soluble chromophore of phenothiazine (PT) unit that is a tricyclic nitrogen-sulfur heterocycle, have been synthesized by introducing an electron-deficient benzothiadiazole (BT) building block copolymerized with either PT or phenothiazine-S,S-dioxide (PT-SS) unit as an oxidized form of PT. The resulting polymers, PPTDTBT and PPTDTBT-SS are fully characterized by UV-vis absorption, electrochemical cyclic voltammetry, X-ray diffraction (XRD), and DFT theoretical calculations. We find that the maximum absorption of PPTDTBT is not only markedly red-shifted with respect to that of PPTDTBT-SS but also its band gap as well as molecular energy levels are readily tuned by the insertion of S,S-dioxides into the polymer. The main interest is focused on the electronic applications of the two polymers in organic field-effect transistors (OFETs) as well as conventional and inverted polymeric solar cells (PSCs). PPTDTBT is a typical p-type polymer semiconductor for OFETs and conventional PSCs based on this polymer and PC71BM show a power conversion efficiency (PCE) of 1.69%. In case of PPTDTBT-SS, the devices characteristics result in: (i) 1 order of magnitude higher hole mobility (μ = 6.9 × 10-4 cm2 V-1 s -1) than that obtained with PPTDTBT and (ii) improved performance of the inverted PSCs (1.22%), compared to its conventional devices. Such positive features can be accounted for in terms of closer packing molecular characteristics owing either to the effects of dipolar intermolecular interactions orientated from the sulfonyl groups or the relatively high coplanarity of PPTDTBT-SS backbone.
Kim, Gyoungsik,Yeom, Hye Rim,Cho, Shinuk,Seo, Jung Hwa,Kim, Jin Young,Yang, Changduk
scheme or table
p. 1847 - 1857
(2012/06/01)

D-A-D low band gap molecule containing triphenylamine and benzoxadiazole/benzothiadiazole units: Synthesis and photophysical properties
Two D-A-D-type low band gap organic dyes based on triphenylamine and benzoxadiazole/benzothiadiazole, 4,7-Bis{5-{4-{2-[4-(N,N-diphenylamino)phenyl]- 1-nitrilethenyl}phenyl}-2-thienyl}-2,1,3-benzoxadiazole (BDNTBX) and 4,7-Bis{5-{4-{2-[4-(N,N-diphenylamino)phenyl]-1-nitrilethenyl}phenyl}-2-thienyl} -2,1,3-benzothiadiazole (BDNTBT) were successfully synthesized. The properties of two compounds were investigated by density functional theory (DFT) calculations, UV-vis absorption spectroscopy, cyclic voltammetry and fluorescence quenching experiment. The calculated ground-state geometries demonstrate intramolecular charge transfer (ICT) occurs in both molecules during the procedure of charge excitation from HOMO to LUMO. From the data in electrochemistry and fluorescence quenching experiments, the molecules reveal lower HOMO energy levels compared with that of P3HT and proper LUMO energy levels to obtain efficient charge separation with PCBM. Two synthesized compounds exhibit broad absorption range covering the whole visible spectral region. These photophysical and electrochemical properties call attention to that our materials are prospective candidates as donor materials for solution-processable organic photovoltaic cells.
Zeng, Shaohang,Yin, Lunxiang,Jiang, Xueying,Li, Yanqin,Li, Kechang
scheme or table
p. 229 - 235
(2012/09/07)

Synthesis and characterizations of benzothiadiazole-based fluorophores as potential wavelength-shifting materials
The synthesized benzothiadiazole-based series fluorophores as potential wavelength-shifting materials exhibit large Stokes shifts (>160 nm) with multiple broad absorbance bands from UV region to 600 nm and a strong fluorescence peak around 700 nm (in CHCl3). Intramolecular charge transfer (ICT) characters of the synthesized compounds are examined using UV-vis and photoluminescence solvatochromic shift measurements. Among the synthesized compounds, the fluorophores with asymmetrical structures exhibit larger Stokes shifts than those with symmetrical structures due to large dipole moment changes upon excitation. The fluorophores with electron-donating methoxyl groups attached to the triphenylamine donors are found to have strong ICT properties. Photophysical experimental results are supported by theoretical calculations using Density Function Theory (DFT) and Time Dependent Density Function Theory (TD-DFT) methods. Calculated frontier molecular orbitals (MOs) of ground states on these fluorophores showed an increase in ICT character up to 50% from HOMO to LUMO. Geometric optimization calculations of the excited state reveal that these fluorophores show a more planar structure for the excited state than the ground state, which allows more π-π* overlap and leads to larger Stokes shifts and higher quantum yields.
Li, Yilin,Scudiero, Louis,Ren, Tianhui,Dong, Wen-Ji
experimental part
p. 51 - 59
(2012/06/18)

Synthesis of π-conjugated copolymers composed of benzo[2,1,3]thiadiazole and thiophene units bearing various alkyl groups and their application to photovoltaic cells
π-Conjugated polymers, PTOTBT, PTEHTBT, and PTt-BTBT, composed of benzothiadiazole as an electron accepting unit and terthiophene as an electron donating unit in the backbone were prepared. PTOTBT, PTEHTBT, and PTt-BTBT contained side chain groups of n-octyl, 2-ethylhexyl, and t-butyl groups, respectively. Solubility, optical and thermal properties of the polymers showed strong dependences on their side chain groups. PTEHTBT having 2-ethylhexyl groups in the side chain exhibited absorption maximum (Imax) at longer wavelength (565 nm) than PTOTBT (534 nm) and PTt-BTBT (495 nm). PTOTBT showed higher thermal stability than the others. The prepared polymers were employed to polymer solar cells (PSCs) with a configuration of ITO/PEDOT-PSS/polymer: PC61BH/LiF/Al. Power conversion efficiency of the PSC-based on PTEHTBT was 1.32%.
Lee, Kwang-Hoi,Lee, Ho-Jin,Kuramoto, Kouji,Tanaka, Yohei,Morino, Kazuhide,Sudo, Atsushi,Okauchi, Tatsuo,Tsuge, Akihiko,Endo, Takeshi
scheme or table
p. 3543 - 3549
(2012/05/04)

A solution-processable deep red molecular emitter for non-doped organic red-light-emitting diodes
A new solution-processable deep red emitter, TCTzC, containing dithienylbenzothiadiazole unit and four alkyl-linked peripheral carbazole groups, is designed and synthesized in high yield by Suzuki coupling reaction. The four peripheral carbazole substituents enhance the hole-transport ability, glass transition temperature, decompose temperature and film forming ability of TCTzC. The single-layered device based on TCTzC shows saturated deep red electroluminescence with a CIE coordinate of (0.70, 0.30). The current efficiency and quantum efficiency of TCTzC is two times higher than the compound without the four peripheral carbazole groups. The higher device performance is obtained when TPBi is applied and the external quantum efficiency could reach to 0.93%.
Wang, Zhiming,Lu, Ping,Xue, Shanfeng,Gu, Cheng,Lv, Ying,Zhu, Qing,Wang, Huan,Ma, Yuguang
experimental part
p. 356 - 363
(2012/06/18)

Structure modification and annealing effect of polymer bulk heterojunction solar cells based on polyfluorene derivatives
Three low bandgap polyfluorene copolymers containing a donor-acceptor-donor moiety have been synthesized via Suzuki and Stille polymerization reactions. Their bandgaps and molecular energy levels (highest occupied molecular orbital and lowest unoccupied molecular orbital) varied with different polymerization methods. The molecular weight of the copolymer increased significantly through copolymerizing with a monomer having a long alkyl side chain. In order to investigate their photovoltaic properties, polymer solar cell devices based on the copolymers were fabricated with a structure of indium tin oxide/poly(styrene sulfonic acid)-doped poly(ethylene dioxythiophene)/copolymers:[6,6]-phenyl-C61- butyric acid methyl ester (PCBM)/LiF/Al under the illumination of AM 1.5G, 100 mW/cm2. We found that the annealing temperature had a profound effect on the power conversion efficiency (PCE) of the devices with a blend of poly[9,9-didodecylfluorene-alt-(bis-thienylene) benzothiadiazole] (PF12-TBT) and PCBM. The PCE of the solar cell based on PF12-TBT/PCBM (1:4) annealing at 70 °C for 20 min was 4.13% with an open-circuit voltage (Voc) of 1.02 V, fill factor of 55.9%, and a short-circuit current (Jsc) of 7.24 mA/cm2. Copyright
Lee, Jung-Feng,Hsu, Steve Lien-Chung,Lee, Po-I,Chuang, Hung-Yi,Chen, Jen-Sue,Chou, Wei-Yang
experimental part
p. 4618 - 4625
(2012/07/14)

A low band gap donor-acceptor copolymer containing fluorene and benzothiadiazole units: Synthesis and photovoltaic properties
A new low band gap copolymer containing dialkylfluorene and 4,7-dithienyl-2,1,3-benzothiadiazole (TBT), poly(fluorenevinylene-alt-4,7- dithienyl-2,1,3-benzothiadiazole) (PF-TBT) was synthesized by Heck cross-coupling polymerization. The copolymer is soluble in common organic solvents such as chloroform, tetrahydrofuran and chlorobenzene. The TGA result indicated that the copolymer possesses good thermal stability. The absorption, electrochemical and photovoltaic properties of PF-TBT were investigated and compared with those of poly(fluorenevinylene-alt-4,7-diphenyl-2,1,3- benzothiadiazole) (PF-DBT) whose structure is similar to PF-TBT. The copolymer exhibited a broad absorption band with an absorption edge close to 700 nm and an optical band gap of 1.82 eV. Cyclic voltammetry studies indicated that the relatively low HOMO energy level assured a higher open circuit voltage (V oc) when PF-TBT is used as the donor material in a photovoltaic cell. The bulk heterojunction (BHJ) solar cell using PF-TBT as the donor and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) as the acceptor with the structure of ITO/PEDOT:PSS/copolymer:PCBM/LiF/Al, exhibited a Voc of 0.86 V, short-circuit current density (Jsc) of 3.97 mA cm -2, fill factor (FF) of 0.35, and a power conversion efficiency (PCE) of 1.18% under one sun of AM 1.5 solar simulator illumination (100 mW cm -2).
Pei, Jianing,Wen, Shanpeng,Zhou, Yinhua,Dong, Qingfeng,Liu, Zhaoyang,Zhang, Jibo,Tian, Wenjing
experimental part
p. 385 - 393
(2011/04/22)

Full emission color tuning in luminogens constructed from tetraphenylethene, benzo-2,1,3-thiadiazole and thiophene building blocks
Full color luminogens are constructed from tetraphenylethene, benzo-2,1,3-thiadiazole and thiophene building blocks. OLED fabricated using one of the luminogens exhibits orange-red electroluminescence with high luminance and efficiencies of 8330 cd m
Zhao, Zujin,Deng, Chunmei,Chen, Shuming,Lam, Jacky W. Y.,Qin, Wei,Lu, Ping,Wang, Zhiming,Kwok, Hoi Sing,Ma, Yuguang,Qiu, Huayu,Tang, Ben Zhong
supporting information; scheme or table
p. 8847 - 8849
(2011/09/16)

Synthesis and characterization of low-band-gap poly(thienylenevinylene) derivatives for polymer solar cells
A series of conjugated polymers containing thienylenevinylene moieties as the electron donor for polymer solar cells were synthesized through Yamamoto and Stille coupling. The structure and device properties of the homopolymer (E)-poly[2,2′-(1,2-ethenediyl)bisthiophene] (PEBT), and two donor-acceptor-type copolymers (E)-poly[2,2′-(1,2-ethenediyl)bisthiophene- alt-4,7-(2,1,3-benzothiadiazole)] (PEBTBT) and (E)-poly[2,2′-(1,2- ethenediyl)bisthiophene-alt-5,5-(4′,7′-di-2-thienyl-2′, 1′,3′-benzothiadiazole)] (PEBTTBT) were investigated. The vinylene group inserted between two thiophene rings has an important role in lowering the band gap of thienylenevinylene derivatives. In addition, the donor-acceptor-type copolymers including a benzothiadiazole unit showed even lower band gap than their own homopolymer due to intramolecular charge transfer (ICT) through their conjugated backbones. As a result, PEBT, PEBTBT and PEBTTBT showed band gaps of 1.77, 1.37 and 1.57 eV, respectively. Bulk heterojunction photovoltaic devices were fabricated using blends of the polymers with [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) and PEBTBT gave the best power conversion efficiency among them, at 1.07% under AM 1.5, 100 mW cm-2. The Royal Society of Chemistry 2011.
Jang, Soo-Young,Lim, Bogyu,Yu, Byung-Kwan,Kim, Juhwan,Baeg, Kang-Jun,Khim, Dongyoon,Kim, Dong-Yu
scheme or table
p. 11822 - 11830
(2011/11/06)

Significantly improved photovoltaic performances of the dithiophene-benzothiadiazole-alt-fluorene copolymers by incorporating carbazole units in fluorene moiety
To exploit an effective way to improve polymeric photovoltaic performance, a series of dithiophene-benzothiadiazole-alt-fluorene copolymers containing carbazole groups at C-9 positions of the alternating fluorene units (PFO-FCz-DBT) were synthesized and characterized. The effect of the carbazole groups on the optophysical, electrochemical, and photovoltaic properties of these copolymers was investigated. By comparison, this type of copolymers with carbazole units exhibited significantly improved photovoltaic properties than poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl- 2′,1′,3′-benzothiadiazole) (PFO-DBT) in the bulk heterojunction solar cells. A maximum power-conversion efficiency (PCE) of 2.41% and a highest short-circuit current density (Jsc) of 9.68 mA cm -2 were obtained for the PFO-FCz-DBT30, which are about two times higher than the corresponding levels for the PFO-DBT30. This work demonstrated that introducing a hole-transporting carbazole unit into copolymer is a simple and effective method to improve the Jsc and PCE. Copyright
Liu, Ming,Wang, Yafei,Zhang, Zhiyong,Li, Jianming,Liu, Yu,Tan, Hua,Ni, Meijun,Lei, Gangtie,Zhu, Meixiang,Zhu, Weiguo
scheme or table
p. 3874 - 3881
(2011/12/21)

Synthesis and electroluminescence properties of white-light single polyfluorenes with high-molecular weight by click reaction
We reported a new way to synthesize single-chain white light-emitting polyfluorene (WPF) with an increased molecular weight using azide-alkyne click reaction. Four basic polymers with specific end-capping, which exhibited high-glass transition temperatures (Tg > 100 °C) and excellent thermal stability, were used as foundations of the WPF's synthesis; a blue-light polymer (PFB2) end-capped with azide groups can easily react with acetylene end-capped polymers (PFB1, PFG1, and PFR1, which are emitting blue-, green- and red-light, respectively) to form triazole-ring linkages in polar solvents such as N,N-dimethylforamide/toluene co-solvent at moderate temperature of 100 °C, even without metal-catalyst. Several WPFs that consist of these four basic polymers in certain ratios were derived, and the polymer light-emitting diode device based on the high-molecular weight WPF was achieved and demonstrated a maximum brightness of 7551 cd/m2 (at 12.5 V) and a maximum yield of 5.5 cd/A with Commission Internationale de l'Eclairage coordinates of (0.30, 0.33) using fine-tuned WPF5 as emitting material.
Lo, Chih-Nan,Hsu, Chain-Shu
scheme or table
p. 3355 - 3365
(2012/05/04)

Low-bandgap poly(4H-cyclopenta[def]phenanthrene) derivatives with 4,7-dithienyl-2,1,3-benzothiadiazole unit for photovoltaic cells
A series of conjugated polymer bearing 4H-cyclopenta[def]phenanthrene (CPP) unit have been synthesized and was evaluated in bulk heterojunction solar cell. The alternating copolymers with CPP unit were incorporated with 4,7-dithienyl-2,1,3-benzothiadiazol
Kim, Jinwoo,Park, Sung Heum,Cho, Shinuk,Jin, Youngeup,Kim, Jaehong,Kim, Il,Lee, Jin Sook,Kim, Joo Hyun,Woo, Han Young,Lee, Kwanghee,Suh, Hongsuk
experimental part
p. 390 - 396
(2011/02/24)

Synthesis of thieno[3,4-b]pyrazine-based and 2,1,3-benzothiadiazole-based donor-acceptor copolymers and their application in photovoltaic devices
Two kinds of thieno[3,4-6]pyrazine-based monomers, 2,3-dimethyl-5,7-di(2- bromothien-5-yl)-thieno[3,4-b]pyrazine and 2,3-diphenyl-5,7-di(2-bromothien-5- yl)-thieno[3,4-p]pyrazine, were synthesized via an improved synthetic route. These two monomers and 4,7-di(2-bromothien-5-yl)-2,l,3-benzothiadiazole were copolymerized with three donor segments (fluorene, carbazole, and indolocarbazole) separately by a Suzuki cross-coupling reaction to give six types of 5,7-dithien-2-yl-thieno[3,4-p]pyrazine (DTTP)-based donor- acceptor (D-A) copolymers (TP1-6) and three types of 5,7-dithien-2-yl-2,l,3- benzothiadiazole (DTBT)-based D-A copolymers (PF-DTBT, PC-DTBT, and PIC-DTBT). The optical properties, electrochemical behavior, and energy levels of these nine copolymers were investigated. The photovoltaic performance of the copolymers was compared and discussed considering their energy levels.
Zhou, Erjun,Cong, Junzi,Yamakawa, Shimpei,Wei, Qingshuo,Nakamura, Motoshi,Tajima, Keisuke,Yang, Chunhe,Hashimoto, Kazuhito
scheme or table
p. 2873 - 2879
(2011/10/09)

Indolo[3,2-b]carbazole-based alternating donor-acceptor copolymers: Synthesis, properties and photovoltaic application
Two new donor-acceptor (D-A) type copolymers, poly{5,11-di(1-decylundecyl) indolo[3,2-b]carbazole-3,9-diyl-alt-4,7-dithien-2-yl-2,1,3-benzothiadiazole- 5′,5″-diyl} (PIC-DTBT) and poly{5,11-di(1-decylundecyl)indolo[3,2-b] carbazole-3,9-diyl-alt-4,7-di(2,2′-bithien-5-yl)-2,1,3-benzothiadiazole- 5′,5″-diyl} (PIC-DT2BT) were synthesized. The polymers have an alternating structure consisting of a large-size fused aromatic ring, indolo[3,2-b]carbazole (IC), as the donor segment and 4,7-dithien-2-yl-2,1,3- benzothiadiazole (DTBT) or 4,7-di(2,2′-bithien-5-yl)-2,1,3- benzothiadiazole (DT2BT) as the acceptor segment. The absorption spectra and the electrochemical properties of PIC-DTBT and PIC-DT2BT indicate that these copolymers have suitable energy levels for photovoltaic application. Polymer photovoltaic devices based on blends of the copolymers and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) have a high open-circuit voltage (>0.9 V) under the illumination of AM 1.5 (100 mW cm-2). The higher power conversion efficiency (PCE) of PIC-DT2BT (2.07%) compared to that of PIC-DTBT (1.47%) suggests that DT2BT could be a promising building block for the efficient D-A type copolymers if the low solubility is overcome by the molecular design of the donor segment. The Royal Society of Chemistry 2009.
Zhou, Erjun,Yamakawa, Shimpei,Zhang, Yue,Tajima, Keisuke,Yang, Chunhe,Hashimoto, Kazuhito
scheme or table
p. 7730 - 7737
(2010/06/11)

A non-planar pentaphenylbenzene functionalized benzo[2,1,3]thiadiazole derivative as a novel red molecular emitter for non-doped organic light-emitting diodes
A novel non-planar pentaphenylbenzene functionalized benzo[2,1,3] thiadiazole derivative (BPTBTD) has been designed and synthesized with only three steps, and applied into non-doped organic light-emitting diodes (OLEDs) as a red molecular emitter. The molecule exhibits good solubility in common organic solvents, excellent thermal stability and film-forming properties. The most important feature is that photoluminescence of BPTBTD shows excellent stablity in different solvents, at different concentrations and in different solid states. Red organic light-emitting diodes were fabricated in a facile non-doped configuration with different thicknesses of emission layers. Saturated red-emission was observed with an emission peak at 621 nm, a maximum external quantum efficiency of 1.0% and a maximum brightness of 1572 cd m-2. Especially, the properties of devices with thick emission layers are two times better than those of the devices with thin emission layers. These results indicate that the non-planar pentaphenylphenyl functional groups substantially suppressed the tendency for molecular aggregation in thin solid films, leading to a very stable photoluminescence and higher efficiency of devices with thicker layers. The Royal Society of Chemistry 2008.
Sun, Xiaobo,Xu, Xinjun,Qiu, Wenfeng,Yu, Gui,Zhang, Hengjun,Gao, Xike,Chen, Shiyan,Song, Yanlin,Liu, Yunqi
body text
p. 2709 - 2715
(2009/12/24)

CONJUGATED POLYMERS CONTAINING SPIROBIFLUORENE UNITS AND THE USE THEREOF
The present invention relates to novel conjugated polymers comprising spirobifluorene units and their use in optoelectronic devices, preferably in, for example, displays based on polymeric organic light-emitting diodes.
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(2010/11/28)

Highly dichroic benzo-2,1,3-thiadiazole dyes containing five linearly π-conjugated aromatic residues, with fluorescent emission ranging from green to red, in a liquid crystal guest-host system
A number of fluorescent benzothiadiazole dyes have been synthesised and their optical properties, when dispersed in a liquid crystal host phase, examined. These dyes have five linearly π-conjugated aromatic ring systems (both with and without ethene and 1
Zhang, Xuelong,Yamaguchi, Rumiko,Moriyama, Keiichi,Kadowaki, Masami,Kobayashi, Takako,Ishi-i, Tsutomu,Thiemann, Thies,Mataka, Shuntaro
p. 736 - 740
(2007/10/03)

Synthesis, photophysics, and electroluminescence of high-efficiency saturated red light-emitting polyfluorene-based polyelectrolytes and their neutral precursors
High-efficiency saturated red light-emitting polyelectrolytes and their neutral precursors: aminoalkyl-substituted polyfluorenes (PFN) with different 4,7-di-2-thieny1-2,1,3-benzothiadiazole (DBT) contents were synthesized by Suzuki coupling reaction. Their quaternized ammonium polyelectrolyte derivatives were obtained through a post-polycondensation treatment on the terminal amino groups. The resulting copolymers are soluble in polar solvents. Narrow band-gap (NBG) DBT units incorporated into the polymer backbone act as exciton traps. As a result, all the polymers emit red light specific to the DBT segments under UV excitation in the solid state. It was found out that the PFN-DBT copolymers show good device performance when high work-function metals, such as Al, are used as the electron-injection cathode replacing conventional low work-function cathodes such as Ca and Ba. It has been shown that these polymers also can be used as electron injection layers (ETL) in double layer structures in polymer light-emitting diodes (PLEDs). Double layer devices, with PFN-DBT as an electron injection layer on top of conventional RGB light-emitting polymers, with high work-function metal cathodes emit light exclusively from the RGB polymers and show high external quantum efficiency. The Royal Society of Chemistry 2005.
Huang, Fei,Hou, Lintao,Shen, Huilin,Jiang, Jiaxing,Wang, Feng,Zhen, Hongyu,Cao, Yong
p. 2499 - 2507
(2007/10/03)

2,1,3-BENZOTHIADIAZOLES FOR USE AS ELECTRONIC ACTIVE COMPONENTS
The invention relates to novel compounds containing 2,1,3-benzothiadiazole. Said compounds can be used as active components (= functional materials) in a series of different applications that can be attributed in the broadest sense to the electronics indu
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(2008/06/13)

Process for preparing a 4,7-bis(5-halothien-2-yl)-2,1,3-benzothiadiazole and a precursor therefor
The present invention is directed to a method for preparing a 4,7-bis(5-halothien-2-yl)-2,1,3-benzothiadiazole, more particularly, 4,7-bis(5-bromothien-2-yl)-2,1,3-benzothiadiazole, and a precursor therefor, namely, a 4,7-bis(thien-2-yl)-2,1,3-benzothiadiazole. The precursor is prepared by contacting in the presence of a palladium catalyst and a solvent a 4,7-dihalo-2,1,3-benzothiadiazole with a thienyl group adding reagent, which can either be a 2-thienylzinc halide, a 2-thienylmagnesium halide, or a 2-thiopheneboronic acid, under such conditions as to form 4,7-bis(thien-2-yl)-2,1,3-benzothiadiazole. The precursor can then be halogenated, preferably brominated, to form the desired dibrominated product, which is a particularly suitable monomer for the preparation of a copolymer of a 9,9-disubstituted fluorene. This copolymer is useful, for example, in polymeric light emitting diode (pLED) applications.
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(2010/02/09)

Strongly red-fluorescent novel donor-π-bridge-acceptor-π-bridge-donor (D-π-A-π-D) type 2,1,3-benzothiadiazoles with enhanced two-photon absorption cross-sections
Novel donor-π-bridge-acceptor-π-bridge-donor (D-π-A-π-D) type 2,1,3-benzothiadiazole fluorescent dyes connected to the N,N-diarylamino terminus via various type π-conjugate spacers exhibits large two-photon absorption cross-sections and high fluorescent quantum yields in orange-red color.
Kato, Shin-Ichiro,Matsumoto, Taisuke,Ishi-I, Tsutomu,Thiemann, Thies,Shigeiwa, Motoyuki,Gorohmaru, Hideki,Maeda, Shuichi,Yamashita, Yoshiro,Mataka, Shuntaro
p. 2342 - 2343
(2008/01/27)

Novel red-emitting fluorene-based copolymers
A series of novel soluble conjugated copolymers derived from 9,9-dioctylfluorene (DOF) and 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DBT) were synthesized by a palladium-catalyzed Suzuki coupling reaction with different feed ratios of DOF to DBT. Owing to exciton confinement on the DBT site, exciton emission is centred on the DBT chromophore and gives rise to saturated red emission. Polyfluorene fluorescence is quenched completely at DBT concentrations as low as 1% in the solid film. Devices based on these copolymers emit a saturated red light. Chromaticity coordinates are around x = 0.70, y = 0.30 for the copolymers. The emission peaks are shifted from 628 nm to 674 nm when DBT content increases from 1 to 35%. The highest quantum efficiency achieved with device configuration of ITO/PEDT/PFO-DBT/Ba/A1 was 1.4% for the copolymer with 15% DBT content.
Hou, Qiong,Xu, Yishe,Yang, Wei,Yuan, Min,Peng, Junbiao,Cao, Yong
p. 2887 - 2892
(2007/10/03)