Diffusible Capping Layer Enabled Homogeneous Crystallization and Component Distribution of Hybrid Sequential Deposited Perovskite.

Nowadays the development of wide-bandgap (WBG) perovskite by thermal evaporation and spin-coating hybrid sequential deposition (HSD) method has special meaning on textured perovskite/silicon tandem solar cells (TSCs). However, the common issues of insufficient reaction caused by blocking of perovskite capping layer have been exacerbated in HSD, because evaporated precursors are usually denser with higher crystallinity and the widely used additive-assisted microstructure is also difficult to access. Here we presented a facile "diffusible perovskite capping layer" (DPCL) strategy to solve this dilemma. With DPCL, crystallization alleviation of perovskite and more diffusion channels of organic salts can be realized simultaneously, contributing to a homogenization process. The resultant perovskite films exhibited complete conversion, uniform crystallization, enhanced quality and reduced defect, leading to obviously improvements in device efficiency, repeatability, and stability. This work offers a way to promote the development of textured tandems a step further. This article is protected by copyright. All rights reserved.