With the view to the poor coexistence between promoting molecular planarity towards improving the intramolecular charge transfer (ICT) effect and preventing charge recombination for dyes in Dye-sensitized solar cells (DSSCs). A novel 2-phenothiazine-amine-based organic dye PTZ-10 is synthesized and applied in DSSCs. The extra benzene and ethynyl conjugated groups are inserted as the isolation groups between the 2-phenothiazine-amine donor and benzothiadiazole auxiliary acceptor to obtain PTZ-17 in order to probe the possibility of reaching the aim of suppressing the charge recombination and strengthening molecular planarity synchronously in a better degree. Our photophysical measurement, electrochemical test and theoretical calculation demonstrate that the introduction of ethynyl and benzene is beneficial to the improvement of ICT effect and the inhibition of charge recombination, which can also be confirmed by the photovoltaic property and EIS study. Therefore, higher short-circuit photocurrent density ($J_{\mathit{sc}}$) and the open-circuit voltage ($V_{\mathit{oc}}$) are exhibited in devices based on PTZ-17, along with the higher photoelectric conversion efficiency (PCE) up to 4.24 % relative to that of 3.37 % in PTZ-10. We demonstrated that the incorporation of different sizes of conjugated groups is a promising candidate to fine-tune the structure-performance of dye molecules in the development of DSSCs’ materials.

鉴于在染料敏化太阳能电池（DSSCs）中促进分子平面性以改善分子内电荷转移（ICT）效应和防止染料的电荷复合之间存在较差的共存性。合成了一种新型 2-吩噻嗪胺基有机染料 PTZ-10，并将其应用于 DSSC。额外的苯和乙炔基共轭基团作为隔离基团插入到 2-吩噻嗪-胺供体和苯并噻二唑辅助受体之间，得到PTZ-17以探索更好程度地同时达到抑制电荷复合和增强分子平面性的目的的可能性。我们的光物理测量、电化学测试和理论计算表明，乙炔基和苯的引入有利于提高ICT效应和抑制电荷复合，光伏特性和EIS研究也证实了这一点。因此，较高的短路光电流密度（${Ĵ}_{\mathit{sc}}$）和开路电压（${五}_{\mathit{oc}}$) 在基于PTZ-17的器件中展示，同时光电转换效率 (PCE) 高达 4.24%，而 PTZ-10 为 3.37%。我们证明，在 DSSCs 材料的开发中，掺入不同大小的共轭基团是微调染料分子结构性能的有希望的候选者。