Fabrication of high-performance and low-hysteresis lead halide perovskite solar cells by utilizing a versatile alcohol-soluble bispyridinium salt as an efficient cathode modifier. Issue 34 (14th August 2017)

• Record Type: Journal Article
• Authors: Chen, Guiting; Zhang, Fan; Liu, Meiyue; Song, Jun; Lian, Jiarong; Zeng, Pengju; Yip, Hin-Lap; Yang, Wei; Zhang, Bin; Cao, Yong
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 34(2017)
• Page Start: 17943
• Page End: 17953
• Publication Date: 2017-08-14
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7ta04995a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A novel bispyridinium salt (FPyBr) is designed as a cathode modifier to achieve high-performance and low-hysteresis fullerene/perovskite solar cells with a maximal PCE of 19.61%. Abstract : A novel alcohol-soluble conjugated bispyridinium salt (FPyBr ) is developed and used as a cathode modifier to improve the cathode interface of planar heterojunction perovskite solar cells (PHJ PVSCs). The excellent electron-withdrawing ability of bispyridinium rings endowsFPyBr with a favorable energy level alignment with phenyl-C60 -butyric acid methyl ester (PCBM) and the cathode ( e.g., Al), which leads to an ideal ohmic contact and efficient electron transport and collection. The deep-lying highest occupied molecular orbital energy level ofFPyBr can also effectively block hole carriers and thus decrease leakage current and hole–electron recombination at the cathode interface. In addition, FPyBr can n-dope PCBM through an anion-induced electron transfer process, which increases the electron mobility of PCBM drastically, thereby diminishing interfacial resistance and promoting electron transport. As a result, by incorporating anFPyBr cathode interlayer with ethanol solvent, high-performance and low-hysteresis PHJ PVSCs with a maximal power conversion efficiency (PCE) of 19.61% can be realized. In contrast, reference devices without any cathode interlayer display a distinctly worse performance, with a PCE of 16.97%. Therefore, this excellent cathode modifier provides a new opportunity to fabricate high performance multilayer PVSCs using low-temperature solution processing without interfacial erosion/mixing.