Interface Engineering of Inverted Wide-Bandgap Perovskite Solar Cells for Tandem Photovoltaics

Wide-bandgap perovskite solar cells (WBG PSCs) have garnered significant research attention due to their encouraging possibility in tandem solar cells (TSCs). Nevertheless, they still confront several challenges, including high open-circuit voltage losses and severe phase instability. These issues are closely associated with the formation of defects, ion migration and energy level mismatch at the interface of wide-bandgap perovskite devices. Meanwhile, the inverted PSCs demonstrate superior stability potential and compatibility with tandem devices, rendering them the most promising application for WBG perovskite materials. Consequently, the interface modulation for such devices has become imperative. In this review, from the perspective of applicability in tandem devices, we firstly provided a concise overview of the background of WBG perovskite research and its efficiency progress in inverted devices. We further discussed interface carrier dynamics and the potential impact of interfaces on such device performance. Afterward, a comprehensive summary of interface engineering in inverted wide-bandgap perovskite (1.60 eV-1.80 eV) solar cells was presented. The research particularly delved into both upper and buried interfaces of WBG absorbers in the inverted PSCs, thoroughly investigating interface design strategies and outlining promising research directions. Finally, this review offers a perspective on the future development of interface engineering for high-performance and large-area WBG PSCs.