The influence of perovskite precursor composition on the morphology and photovoltaic performance of mixed halide MAPbI3-xClx solar cells. (15th March 2018)

• Record Type: Journal Article
• Authors: Tombe, Sekai; Adam, Getachew; Heilbrunner, Herwig; Yumusak, Cigdem; Apaydin, Dogukan Hazar; Hailegnaw, Bekele; Ulbricht, Christoph; Arendse, Christopher J.; Langhals, Heinz; Iwuohaa, Emmanuel; Sariciftci, Niyazi Serdar; Scharber, Markus C.
• Is Part Of: Solar energy. Volume 163(2018)
• Page Start: 215
• Page End: 223
• Publication Date: 2018-03-15
• Subjects: Perovskite precursor -- Morphology -- Photovoltaic performance -- Electron transport layer -- Shelf stability; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2018.01.083
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Perovskite precursor composition affects the crystallization and film morphology. Film morphology determines photovoltaic performance and hysteresis phenomena. Energy level alignment of the ETL and its interface is crucial for high PCE. Better shelf stability observed with H3 CNH3 PbI3-x Clx compared to H3 CNH3 PbI3 . Abstract: A set of various perovskite precursor formulations was investigated to elucidate correlations between precursor composition and the crystal structure, film morphology as well as photovoltaic activity of H3 CNH3 PbI3-x Clx perovskite solar cells. Three precursor solutions in dimethylfromamide (DMF) with defined ratios of lead(II) halide (PbI2 and/or PbCl2 ) and methylammonium halide (H3 CNH3 I (MAI) and H3 CNH3 Cl (MACl)) such as 1:3 (PbCl2 :MAI), 1:1:4 (PbI2 :PbCl2 :MAI) and 1:1:1 (PbI2 :MAI:MACl) were used to prepare solar cells in primarily ambient atmosphere. Processing the 1:3 (PbCl2 :MAI) solution in ambient atmosphere yielded perovskite films with rather non-uniform morphology and devices with moderate performance. Perovskite thin films prepared from the 1:1:4 (PbI2 :PbCl2 :MAI) and 1:1:1 (PbI2 :MAI:MACl) formulation showed nearly identical features, high crystallinity, large and compact micrometer-sized crystal domains, and good photovoltaic performance. This indicates that the overall ionic composition in the precursor solution is crucial for the perovskite formation, the source of these ions, however, appears nonrelevant. Furthermore, the effect of different electron transport layers (ETL), PCBM, bis -PCBM, and N -[4-(benzothiadiazol-4-yl)phenyl]- N ′-(1-nonyldecyl)perylene-3, 4, 9, 10-tetracarboxdimide (a-PTCDI) on the photovoltaic performance was analyzed. The highest hysteresis-free power conversion efficiency (PCE) was achieved with PCBM (12.8%) followed by a-PTCDI (8.4%) and bis -PCBM (6%). The degradation of MAPbI3-x Clx based devices stored in nitrogen atmosphere was primarily revealed by a loss in fill factor.