给受体共混质量比对P3HT:PCBM薄膜结构和器件性能的影响

以聚3-己基噻吩(P3HT)为给体、6,6]-苯基-C61-丁酸甲酯(PCBM)为受体的光伏体系作为研究对象,采用溶剂退火的后处理方法制备薄膜样品,利用紫外-可见(UV-Vis)吸收光谱、原子力显微镜(AFM)、X射线衍射(XRD)等测试手段分别对共混膜样品的形貌和结构进行表征,同时利用熵值统计方法对AFM形貌图像进行分析处理.并在此基础上制备太阳能电池器件,其结构为氧化铟锡导电玻璃/聚3,4-乙撑二氧噻吩:聚苯乙烯磺酸盐/聚3-己基噻吩:6,6]-苯基-C61-丁酸甲酯/金属铝(ITO/PEDOT:PSS/P3HT:PCBM/Al),研究了给受体共混比例(质量比)对活性层薄膜以及电池性能的影响.结果表明,受体PCBM含量的增加会影响P3HT给体相的有序结晶,当给受体比例为1:1时,活性层薄膜具有较宽的紫外-可见吸收特征,且具有较好的相分离和结晶度,基于该样品制备的电池器件其光电转换效率达到三种比例的最大值(2.77%).表明退火条件下,改变给受体比例可以影响活性层的微纳米结构而最终影响电池的光电转换效率.

Influence of Donor and Acceptor Mass Ratios on P3HT:PCBM Film Structure and Device Performance

Organic bulk heterojunction photovoltaic devices based on poly(3-hexylthiophene)(P3HT,donor) and 6,6]-phenyl-C61-butyric acid methyl ester(PCBM,acceptor) were fabricated using solvent annealing treatment.The nanoscale morphology and structure of the P3HT:PCBM blend films were characterized by UV-Vis absorption spectroscopy(UV-Vis),atomic force microscopy(AFM),and X-ray diffraction(XRD) analyses.In addition,the AFM images were processed using the entropyfilt method.The performances of the P3HT:PCBM devices with different mass ratios were measured,having a structure of indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)/P3HT:PCBM/aluminium(Al).The results showed that the crystallinity of the P3HT polymer can be disturbed by the relative amount of PCBM molecules.The 1:1(mass ratio) blend film possessed the greatest absorption width by UV-Vis absorption,as well as good phase separation and a high level of crystallinity,providing the best device performance(2.77%).This study indicates that the donor and acceptor mass ratios do have an influence on the nanoscale morphology and structure of the blend films,which can in turn affect the device performance.