Crystallization Modulation of Wide-Bandgap Perovskites on Textured Silicon for Tandem Solar Cells

Abstract

Despite the rapid progress of monolithic perovskite-silicon tandem solar cells on planar and nanotextured silicon subcells, achieving high-performance tandem devices directly adopting commercially compatible crystalline silicon cells remains difficult because of the hardly controllable fabrication of wide-bandgap perovskite films on top. Herein, we developed a facile crystallization modulation strategy for the vapor–solution hybrid two-step deposited wide-bandgap perovskites on fully textured crystalline silicon substrates. We comprehensively investigate the conversion process of thermally evaporated inorganic frameworks to the desired perovskite phase under different humid air conditions, and successfully disassemble the moisture- and thermal-induced complex effects on the crystallization and degradation of perovskite films. With a carefully modulated sequential annealing process in ambient, we obtain high-quality wide-bandgap perovskite films conformally grown on fully textured silicon substrates with reduced defects and homogeneous composition distribution, enabling the achievement of perovskite-silicon tandems with a certified PCE of 31.4%, which is among the best-performing tandem devices utilizing commercial silicon subcells.