We report on the design, synthesis and characterization of light harvesting small molecules for use in solution-processed small molecule bulk heterojunction (SM-BHJ) solar cell devices. These molecular materials are based upon an acceptor/donor/acceptor (A/D/A) core with donor endcapping units. Utilization of a dithieno(3,2-b;2′,3′-d)silole (DTS) donor and pyridal[2,1,3]thiadiazole (PT) acceptor leads to strong charge transfer characteristics, resulting in broad optical absorption spectra extending well beyond 700 nm. SM-BHJ solar cell devices fabricated with the specific example 5,5′-bis7-(4-(5-hexylthiophen-2-yl)thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine}-3,3′-di-2-ethylhexylsilylene-2,2′-bithiophene (6) as the donor and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor component showed short circuit currents above −10 mA cm−2 and power conversion efficiencies (PCEs) over 3%. Thermal processing is a critical factor in obtaining favorable active layer morphologies and high PCE values. A combination of UV-visible spectroscopy, conductive and photo-conductive atomic force microscopies, dynamic secondary mass ion spectrometry (DSIMS), and grazing incident wide angle X-ray scattering (GIWAXS) experiments were carried out to characterize how thermal treatment influences the active layer structure and organization.
我们报告了用于溶液处理小分子本体异质结 (SM-BHJ) 太阳能电池器件的光捕获小分子的设计、合成和表征。这些分子材料基于带有供体封端单元的受体/供体/受体 (A/D/A) 核心。利用二
噻吩并(3,2-b;2',3'-d)
硅咯 (D
TS) 供体和
吡啶并[2,1,3]
噻二唑 (
PT) 受体可产生强大的电荷转移特性,从而产生广泛的光学吸收光谱范围远远超出 700 nm。 SM-BHJ太阳能电池器件采用具体示例5,5'-bis7-(4-(5-hexylthiophen-2-yl)thiophen-2-yl)-[1,2,5]thiadiazolo[3, 4-c]
吡啶}-3,3'-二-2-乙基己基亚甲
硅基-2,2'-联
噻吩(6)作为供体,[6,6]-苯基-C71-
丁酸甲酯(PC71BM)作为供体受体组件显示短路电流高于−10 mA cm−2,功率转换效率 (PCE) 超过 3%。热处理是获得良好的有源层形貌和高 PCE 值的关键因素。结合紫外可见光谱、导电和光电导原子力显微镜、动态二次质量离子光谱 (DSIMS) 和掠入射广角 X 射线散射 (GIWAXS) 实验来表征热处理如何影响活性层结构和组织。