1256138-50-7

Upstream product

• 1187970-52-0 2,7-bis-trimethylsilyl-benzo [1,2-b:6,5-b’] dithiophene-4,5-dione 
• 1256138-44-9 benzo[1,2-b:6,5-b′]dithiophene-4,5-diamine 
• 1415761-29-3 N,N'-dihydroxythieno[3,2-g][1]benzothiophene-4,5-diimine 
• 24243-32-1 benzo<2,1-b;3,4-b'>dithiophen-4,5-dione 

Downstream Products

• 1415761-37-3 5,8-dibromodithieno[3′,2’:3,4;2′′,3’’:5,6]benzo[1,2-c][1,2,5]thiadiazole 

Relevant academic research and scientific papers

The effect of thiadiazole out-backbone displacement in indacenodithiophene semiconductor polymers

We describe the synthesis and characterisation of two new polymers consisting of an electron-rich backbone containing indacenodithiophene (IDT) and dithiophene (DT) with the electron-poor units benzothiadiazole (BT) and benzopyrazolothiadiazole (BPT) fused on top of DT. The effect of this substitution has been studied and discussed by optical, electrochemical and computational means. Despite having very similar molecular distribution as well as thermal and electrochemical properties, the addition of the stronger electron-withdrawing BPT unit leads to a substantial change on the absorption properties by promoting the intramolecular charge transfer (ICT) band alongside the π-π. Furthermore, we also report organic field effect transistor and solar cells device results, giving hole mobilities of 0.07 cm2 V-1 s-1 with low threshold voltage (10 V) and power conversion efficiencies of up to 2.2%.

Selenium-containing D?A?D-type dopant-free hole transport materials for perovskite solar cells

A novel selenium-containing D?A?D-type dopant-free hole-transport material with fused dithienobenzoselenadiazole acceptor unit (DTBS) was designed, synthesized and applied in a perovskite solar cell (PSC). In addition, two dopant-free hole-transport materials were prepared as references with similar structure but different chalcogen elements (O for DTBF and S for DTBT) being used. The impact of chalcogen atom variation in the dopant-free hole-transport materials on the properties is systematically investigated, such as the physicochemical, electrochemical, morphological feature and photovoltaic properties in PSC. The PSC fabricated with DTBS shows the power conversion efficiency value of 15.09% due to its high fill factor, which is much higher than those with the references (13.31% for DTBF and 11.65% for DTBT). Moreover, the PSCs fabricated with DTBS without encapsulation are operational with 77.8% performance retention under air condition after 30 days, which is much better than those prepared with doped spiro-OMeTAD (43.6%). The great stability for the DTBS-based PSC may be owing to the excellent thin film morphology and hydrophobicity of DTBS. Our work demonstrates that the selenium-containing organic compounds can act as the dopant-free hole-transport materials in PSC with both high efficiency and long stability being achieved.

A Facile Synthesized Polymer Featuring B-N Covalent Bond and Small Singlet-Triplet Gap for High-Performance Organic Solar Cells

High-efficiency organic solar cells (OSCs) largely rely on polymer donors. Herein, we report a new building block BNT and a relevant polymer PBNT-BDD featuring B-N covalent bond for application in OSCs. The BNT unit is synthesized in only 3 steps, leading to the facile synthesis of PBNT-BDD. When blended with a nonfullerene acceptor Y6-BO, PBNT-BDD afforded a power conversion efficiency (PCE) of 16.1 % in an OSC, comparable to the benzo[1,2-b:4,5-b′]dithiophene (BDT)-based counterpart. The nonradiative recombination energy loss of 0.19 eV was afforded by PBNT-BDD. PBNT-BDD also exhibited weak crystallinity and appropriate miscibility with Y6-BO, benefitting of morphological stability. The singlet–triplet gap (ΔEST) of PBNT-BDD is as low as 0.15 eV, which is much lower than those of common organic semiconductors (≥0.6 eV). As a result, the triplet state of PBNT-BDD is higher than the charge transfer (CT) state, which would suppress the recombination via triplet state effectively.

A family of donor-acceptor photovoltaic polymers with fused 4,7-dithienyl-2,1,3-benzothiadiazole units: Effect of structural fusion and side chains

A new optoelectronic building block, dithieno[3′,2′:3, 4;2″,3″:5,6]benzo[1,2-c][1,2,5]thiadiazole, was designed by applying a fusion strategy on 4,7-dithienyl-2,1,3-benzothiadazole (DTBT) and named as fDTBT. In combination with benzo[1,2-b:4,5-b′]dithiophene (BDT), fDTBT was used for the construction of a family of donor-acceptor copolymers, P(BDT n-fDTBT), with different side chains (n is carbon number of the side chain and varies from 8, 10, 12, 16, 20, to 24). It was found that the side chains have great impact on processing and photovoltaic properties of the polymers. P(BDTn-fDTBT) (n = 8, 10, and 12) bearing small alkyl side chains show poor solubility even in hot solvents. P(BDTn-fDTBT) (n = 20 and 24) have good solubility but inferior photovoltaic performance with an efficiency of 1.04% and 0.49%, respectively. Only P(BDT16-fDTBT) having 2-hexyldecyl side chain possesses both suitable solution processability and good photovoltaic properties with an efficiency around 4.36%. The comparison between P(BDT16-fDTBT) with the nonfused reference polymer P(BDT20-DTBT) reveals that the structural fusion on DTBT endows the polymer a deeper HOMO energy level and a better film morphology when blending with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), finally resulting in improved photovoltaic performance.

Efficient synthesis of benzo[1,2- b:6,5- b']dithiophene-4,5-dione (BDTD) and its chemical transformations into precursors for π-conjugated materials

A straightforward synthesis of the fused-aromatic dione benzo[1,2-b:6,5-b']dithiophene-4,5-dione (BDTD) has been developed. This fused-aromatic dione was subjected to various chemical transformations to generate diverse molecules with potential use in π-conjugated materials for organic electronics.