Coating dynamics in two-step hybrid evaporated/blade-coated perovskites for scalable fully-textured perovskite/silicon tandem solar cells

Abstract

Perovskite/silicon tandem solar cells hold great promise for wide-scale photovoltaic deployment. Despite the achievement of high power conversion efficiencies (PCEs) exceeding 33%, the commonly used spin-coating technique for perovskite deposition encounters substantial scalability challenges. To address this, we investigate the potential of the two-step hybrid evaporation/blade-coating method for perovskite manufacturing on silicon with industry-standard texturing. Combining experimental results with theoretical considerations on meniscus formation, we comprehensively analyze the influence of fluid mechanisms involved in the blade-coating process and find that the final perovskite film properties can be controlled through two main properties: wet film thickness and solvent's evaporation rate. Furthermore, the study finds that unlike one-step blade-coated perovskites, where increased speed results in a U-shaped, speed-dependent thickness for evaporation and Landau–Levich coating regimes, the hybrid evaporation/blade-coating method reveals a different S-shaped curve, correlating speed with perovskite conversion rate. Good perovskite properties of fully-textured perovskite/silicon tandem solar cells are demonstrated by open-circuit voltages exceeding 1900 mV and a PCE approaching 28%. This work identifies key challenges in scalable perovskite deposition with the hybrid method, deriving learnings that can be transferred to other meniscus-based hybrid industrial techniques, and reinforces the need for film optimization with scalable methods at the early R&D stage.