Interface engineering of inverted wide-bandgap perovskite solar cells for tandem photovoltaics

Wide-bandgap perovskite solar cells (WBG PSCs) have garnered significant research attention for their potential in tandem solar cells. However, they face challenges such as high open-circuit voltage losses and severe phase instability. These issues are primarily owing to the formation of defects, ion migration, and energy level mismatches at the interface of WBG perovskite devices. Meanwhile, inverted PSCs demonstrate superior stability potential and compatibility with tandem devices, making them the most promising application for WBG perovskite materials. Consequently, interface modulation for such devices has become imperative. In this review, from the perspective of applicability in tandem devices, we first provided a concise overview 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, we presented a comprehensive summary of interface engineering in inverted WBG perovskite (1.60 eV–1.80 eV) solar cells. The research particularly explored both the upper and buried interfaces of WBG absorbers in the inverted PSCs, thoroughly investigating interface design strategies and outlining promising research directions. Finally, this review provides insight into the future development of interface engineering for high-performance and large-area WBG PSCs.