Interface engineering of Tin(IV) oxide electron transport layer with Yttrium(III) fluoride for efficient carbon-based perovskite solar cells

Abstract

Carbon-based perovskite solar cells (C–PSCs) are the most promising technology to meet global energy demands at a reasonable price. In the current study, to assemble efficient and stable C–PSCs, the interface between the tin oxide electron transport layer and the mixed-cation perovskite layer was tailored by coating yttrium fluoride (YF3) material over the tin oxide layer. Results show that YF3–SnO2 ETL produces a more suitable substrate for perovskite fabrication, causing the formation of a perovskite layer with enlarged grains and a lower PbI2 residual. In addition, the results indicate that YF3 treatment could boost the conductivity of SnO2, reduce defects in the mixed-cation perovskite layer, and suppress nonradiative recombination in the C–PSCs. YF3-based interface engineering brought champion C–PSCs with an efficiency of 14.01% under simulated illumination of 100 mW cm−2, which was considerably higher than the 11.58% recorded for control C–PSCs. After 168 days of aging, the unsealed, modified C-PSC devices can demonstrate superior ambient air stability behavior conditions and retain 95% of their initial performance.