Challenges and Perspectives toward Future Wide-Bandgap Mixed-Halide Perovskite Photovoltaics

Wide-bandgap (WBG) perovskite solar cells (PSCs) are acknowledged as promising candidates for multijunction tandem and building photovoltaics, which attract broad research interest in related research communities. However, the performance of WBG PSCs based on the mixed-halide perovskites still lags far behind their pure-iodide counterparts because of the complex compositional evolution, huge photovoltage deficits, and intrinsic spectral losses. Here, by comprehensively understanding the representative WBG PSCs, the main "WBG drawbacks" from the device point of view are discussed in-depth and three intrinsic critical issues for the growth of high-quality WBG perovskites are proposed. The prospects for WBG PSCs toward future advancements and commercialization are also presented to guide the coming research hot spots.