We report improved device performance of poly(3-hexylthiophene) (P3HT) and [6,6]phenyl C61butyric acid methyl ester (PCBM)-based inverted bulk-heterojunction (BHJ) solar cells through the modified interface of the TiO2/BHJ with a series of carboxylic acid functionalized self-assembled monolayers (SAMs). The SAMs reduce the series resistance and improve the shunt resistance of the cell leading to increased fill factor and photocurrent density. Different aspects of device improvement can be affected depending on the nature of the SAMs. Modification with a C60-SAM shows the largest enhancement leading to a 35% improvement (η = 3.78%) over unmodified inverted devices (η = 2.80%). This SAM serves multiple functions to affect the photoinduced charge transfer at the interface to reduce the recombination of charges, passivation of inorganic surface trap states, improve the exciton dissociation efficiency at the polymer/TiO2 interface as well as a template to influence the overlayer BHJ distribution of phases, morphology and crystallinity leading to better charge selectivity and improved solar cell performance.
我们报告了通过改进的 TiO2/BHJ 界面,改进了基于聚(
3-己基噻吩)(P3HT)和 [6,6]苯基 C61
丁酸甲酯(PCBM)的倒置体异质结(BHJ)太阳能电池的器件性能一系列
羧酸功能化的自组装单层(S
AM)。 S
AM 降低了电池的串联电阻并改善了分流电阻,从而提高了填充因子和光电流密度。根据 S
AM 的性质,设备改进的不同方面可能会受到影响。使用 C60-S
AM 进行的修改显示出最大的增强,比未修改的倒置器件 (η = 2.80%) 提高了 35% (η = 3.78%)。该 S
AM 具有多种功能,可影响界面处的光致电荷转移,以减少电荷复合、钝化无机表面陷阱态、提高聚合物/TiO2 界面处的激子解离效率以及影响覆盖层 BHJ 分布的模板相、形态和结晶度的变化导致更好的电荷选择性和改进的太阳能电池性能。