The University of Electronic Science and Technology of China, has collaborated with Tongwei, a solar technology firm headquartered in Chengdu, and the National Institute of Measurement and Testing Technology. The cooperation was aimed at enhancing perovskite-silicon tandem solar cells by solving challenges in the production of wide-bandgap perovskite films on commercially compatible textured crystalline silicon subcells. Researchers applied a vapor–solution hybrid two-step deposition process and investigated how humidity and temperature were influencing crystallization and degradation of perovskite films. A sequential annealing method in ambient air was developed, which has reduced defects and improved composition uniformity in the films. This process has enabled conformal wide-bandgap perovskite growth on textured silicon substrates. Tongwei said the study has resulted in certified tandem devices achieving 31.4% efficiency, which is among the highest recorded using commercial silicon cells.