In-situ passivation of TiO2 mesoporous scaffold with nano-sized heteropolyacid for boosting the efficiency of the perovskite solar cells. (1st February 2020)

• Record Type: Journal Article
• Authors: Dong, Guohua; Xia, Debin; Yang, Yulin; Zhang, Wenzhi; Fan, Ruiqing; Sui, Lili; Su, Liqiang; Zhao, Yunpeng; Yang, Peiqing; Li, Yixuan
• Is Part Of: Electrochimica acta. Volume 332(2020)
• Publication Date: 2020-02-01
• Subjects: Perovskite solar cells -- Passivation -- TiO2 -- H3PW12O40·nH2O -- PW12/TiO2; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.135427
• Languages: English
• ISSNs: 0013-4686

Abstract

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 (H3 PW12 O40 ·nH2 O). Due to the strong interaction between H3 PW12 O40 ·nH2 O 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. Graphical abstract: Passivation of the TiO2 mesoporous layer with a nanoscale dispersed heteropolyacid can apparently improve photovoltaic performance of perovskite solar cells due to the enhanced surface morphology of PW12 /TiO2, increased conductivity, and improved photo-generated electron extraction/dissociation/transportation inside the PSCs. Image 1 Highlights: In-situ Passivation of TiO2 was proposed with nano-sized H3 PW12 O40 ·nH2 O. A more uniform PW12 /TiO2 ETL can be obtained due to the PW12 passivation. This PW12 /TiO2 ETL shows outstanding physicochemical properties. An apparent PCE enhancement of PSCs can be demonstrated from 15.05% to 18.20%.