dithieno[3,2-b:2′,3′-d]pyrrole (DTP) containing A–D–A oligomers for use in solution-processed bulk heterojunction solar cells is presented. This series allows investigation of the effect of alkyl chains attached to the thiophene moieties or the nitrogen of the DTP unit on the thermal and physical properties of the oligomers. The photoactivelayers were probed using absorption spectroscopy, grazing incident
提出了一系列用于溶液处理的本体异质结太阳能电池的含有A–D–A低聚物的二噻吩并[3,2- b:2',3'- d ]吡咯(DTP)的合成。该系列可以研究连接到噻吩部分或DTP单元氮上的烷基链对低聚物的热和物理性质的影响。使用吸收光谱,掠入射X射线衍射和原子力显微镜对光敏层进行探测。从这些实验中发现,连接至噻吩单元的己基链有助于在太阳能电池装置中获得良好的堆积和高填充因子。对于太阳能电池的制造,PEDOT:PSS和V 2 O 5都可以将其作为空穴传输层进行研究,并使用PDMS作为溶剂添加剂。获得了高达1.1 V的高开路电压,适度的短路电流密度和高达0.63的高填充因子,从而产生了高达5.3%的功率转换效率。
Synthesis and properties of fluorene or carbazole-based and dicyanovinyl-capped n-type organic semiconductors
Dicyanovinyl-substituted compounds as electron transport materials are rarely studied, especially oligomers. A new series of fluorene or carbazole-based and dicyanovinyl-capped oligomers consisting of benzene or thiophene segments were synthesized using the Stille coupling reaction and their physical properties were investigated. Optical spectra show that the introduction of electron-accepting groups induces an intramolecular charge transfer, resulting in a shift of the absorption onset toward longer wavelengths. Moreover, the optical spectra of their films show intermolecular interactions, leading to bathochromic shifts with respect to the spectra in solution. Cyclic voltammetry indicates that they have suitable HOMO and LUMO energy levels, and the oligomers containing thiophene segments show lower LUMO levels. The X-ray crystallography of compound FTCN shows that the compound exhibits extended π stacking of the molecules. Thermal analysis reveals that they are thermally stable and no phase transition was observed at low temperatures.
Efficient synthesis of a series of terminally dicyanovinyl (DCV)‐substituted oligothiophenes, DCVnT 1–6, without solubilizing side chains synthesized via a novel convergent approach and their application as electron donors in vacuum‐processed m‐i‐p‐type planar and p‐i‐n‐type bulk heterojunction organic solar cells is described. Purification of the products via gradient sublimation yields thermally
Covalent bridging of the central 2,2′-bithiophene of α,ω-bis(dicyanovinyl)quaterthiophene derivatives leads to a reduced band gap and efficient organic solar cells.