All‐Perovskite Tandem Solar Cells: Rapid Development of Thin Film Photovoltaic Technology

Abstract Organic–inorganic halide perovskite materials have attracted wide attention and research because of their adjustable bandgap, high absorption coefficient, and simple preparation methods. The power conversion efficiency (PCE) of single‐junction perovskite cells has increased from 3.8% to 26% in recent years. Using bandgap complementary photovoltaic technology to pair wide‐bandgap with low bandgap perovskites to build all‐perovskite tandem solar cells (all‐PTSCs) is one of the best strategies to break the limitation of Shockley‐Queisser (SQ), which is expected to obtain a PCE higher than 30% at low cost. In this brief review, the structure and working principle of all‐PTSCs is first introduced. Then the latest progress of each component of tandem devices is reviewed according to the two different tandem modes of 2‐terminal (2‐T) and 4‐terminal (4‐T). Besides, the existing problems and optimization strategies of different components are discussed. Finally, the future development of all‐PTSCs is prospected.