Influence of Lead Source on the Film Morphology of Perovskites Spin-Coated on Planar and Mesoporous Architectures under Ambient Conditions

Photovoltaics based on lead halide perovskite (LHP) materials have attracted interest in recent years due to rapidly increasing performance conversion efficiency (PCE) and low material cost. However, current fabrication methods for perovskite solar cells (PSC) are mainly done under inert environments primarily due to the material's sensitivity to moisture and oxygen. The development of practical upscaling technology for perovskite solar cells requires a fabrication technique that does not require inert conditions. In this report, we studied the significance of lead source and device architecture on the film quality of LHP when fabricated under ambient atmosphere (relative humidity, RH > 60%). Results suggest that LHP prepared from PbI2 salt has poor material morphology and optical properties regardless of the device architecture adopted. On the other hand, LHP prepared from both PbCl2 and PbAc2 showed superior morphology and optical quality when prepared on mesoporous TiO2 scaffold in comparison to a planar TiO2 layer. By utilizing an ambient-compatible and cost-efficient hole transport layer (HTL) copper(I) thiocyanate (CuSCN), we test the film quality by fabricating a full PSC using PbAc2 as the lead source under ambient conditions, with PCE reaching > 8.0%. [GRAPHICS] .

Automated summary

Photovoltaics based on lead halide perovskite (LHP) materials have gained interest for their high conversion efficiency and low cost. However, current fabrication methods require inert environments. This study investigates the effect of lead source and device architecture on the quality of LHP films prepared under ambient conditions. Results show that LHP prepared from PbI2 has poor material morphology, while LHP prepared from PbCl2 and PbAc2 on a mesoporous TiO2 scaffold show superior quality. A full perovskite solar cell with over 8.0% PCE is fabricated using an ambient-compatible hole transport layer.