Cesium carbonate modified electron transport layer for improving the photoelectric conversion efficiency of planar perovskite solar cells. (15th June 2020)

• Record Type: Journal Article
• Authors: Lv, Chuang; Du, An; Ma, Ruina; Gao, Fan; Yang, Huazhen; Fan, Yongzhe; Zhao, Xue; Cao, Xiaoming
• Is Part Of: Materials science in semiconductor processing. Volume 112(2020)
• Publication Date: 2020-06-15
• Subjects: Perovskite solar cells -- Electron transport layers -- Interface modification -- Cs2CO3; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105014
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: TiO2 is a commonly used material in the electron transport layers (ETLs) of perovskite solar cells (PSCs) but its defects restrict the development of PSCs. In this study, cesium carbonate (Cs2 CO3 ) was used to modify the TiO2 ETLs because of its excellent electron injection ability. The new structure of the PSC was FTO/TiO2 /Cs2 CO3 /perovskite (MAPbI3 )/sprio-OMETAD/back electrode. As expected, adding Cs2 CO3 increased the champion photoelectric conversion efficiency (PCE) from 9.2% to 12.8% in comparison with unmodified solar cells, and the device maintained 78% of the original efficiency after 250 h. Moreover, the reduction of defects in the TiO2 ETLs reduced the coincidence probability of carriers after modification with Cs2 CO3 . Due to the excellent electron injection ability of Cs2 CO3, the modified ETLs yielded lower work functions and smaller energy level barriers, which makes the energy levels between the TiO2 ETL and the MAPbI3 layer well-matched, and reduced the carrier coincidence probability.