胆甾液晶掺杂活性层对有机太阳能电池性能的影响

Efficiency improvement in organic solar cells by doping cholesteric liquid crystal

以poly(3-hexylthiophene)(P3HT)为电子给体,indene-C60bisadduct(ICBA)为电子受体,通过掺杂不同浓度胆甾液晶氯化胆甾醇制备了有机体异质结太阳能电池.结果表明,适当浓度掺杂使器件的开路电压提高到了0.78 V,但短路电流密度却有所降低,填充因子几乎不变,能量转换效率提高了10%.利用X射线、光致发光、原子力显微镜及紫外-可见吸收光谱进行表征,发现液晶掺杂对活性层的结晶度、分子内部排列情况、薄膜表面形貌和光吸收特性等都有明显影响.

A series of poly（3-hexylthiophene） （P3HT）/indene-C60 bisadduct （ICBA） bulk heterojunction polymer solar cells is fabricated with different cholesteric liquid crystalline （LC）-cholesteryl chloride doping concentrations. The open circuit voltage （Voc） is increased from 0.78 V to 0.65 V, meanwhile the short circuit current density （Jsc） is reduced from 4.23 mA·cm^-2 to 4.10 mA·cm^-2 when the LC doping concentration is 5%, and fill factor is almost unchanged. The optimized power conversion effciency of polymer solar cells （PSCs） with LC doping is about 1.51%. The crystallinity of the active layer and the light absorption characteristics are analyzed by X-ray diffraction, photoluminescence, UV-visible absorption spectroscopy and atomic force microscope, respectively.