In-situ passivation of TiO2 mesoporous scaffold with nano-sized heteropolyacid for boosting the efficiency of the perovskite solar cells
By Dong, Guohua; Xia, Debin; Yang, Yulin; Zhang, Wenzhi; Fan, Ruiqing; Sui, Lili; Su, Liqiang; Zhao, Yunpeng; Yang, Peiqing; Li, Yixuan
Published in Electrochimica Acta
2019
Abstract
TiO2 is a widely used electron transport layer for high efficiency perovskite solar cells. However, many intrinsic shortcomings seriously deteriorate the devices performance. Herein, we demonstrate a facile and effective approach to improve the photovoltaic performance by passivating the TiO2 mesoporous layer with a nanoscale dispersed 12-tungstophosphoric heteropolyacid (H3PW12O40·nH2O). Due to the strong interaction between H3PW12O40·nH2O and TiO2, the passivated TiO2 mesoporous electron transport layer (hereafter denoted as PW12/TiO2) with an optimal weight ratio shows a more uniform coverage on the underlying substrate in comparison with the bare TiO2. Furthermore, the resulted PW12/TiO2 also shows an obviously improved conductivity and significantly increased photoluminescence quenching for the perovskite emission. Thereby, this strategy leads to an apparently improved photovoltaic performance of perovskite solar cells with power conversion efficiency enhancement from 15.05% to 18.20%. In conclusion, our present study provides an effective approach for further improving the performance of perovskite solar cells by passivating the mesoporous electron transport layer with the well-known heteropolyacids.