Layer-by-layer spray coating of a stacked perovskite absorber for perovskite solar cells with better performance and stability under a humid environment

Abstract

Perovskite is an emerging material for high performance solar cell application with low-cost solution-processable fabrication. As an ink, perovskite composition can be easily modified to create semi-transparent solar cells for window replacement. To enable scalable large-scale production, the spray process is one of the major candidates. In this work, we developed sequential spray deposition (SSD) to create double layer absorbers from different dimensional perovskites. SSD, for the first time, achieves layer-by-layer deposition of different perovskite materials for stacked architecture. To demonstrate the benefits, we spray-coated lower dimension, more stable perovskite onto high performance yet sensitive 3D semi-transparent perovskite. SSD performed under a humid environment (40 - 50% RH) brings about better film stability and retains good performance of 3D perovskite. Sequential spray deposition opens new routes for various stacking designs and large-scale production under economical ambient conditions.