Spontaneous Construction of Multidimensional Heterostructure Enables Enhanced Hole Extraction for Inorganic Perovskite Solar Cells to Exceed 20% Efficiency

CsPbI 3− x Br x ‐based organic‐free perovskite has emerged as a superstar photovoltaic material not only because of its superior photoelectronic properties but also its outstanding thermal and chemical stability. Unfortunately, the significant energy loss resulting from its nonradiative recombination has become a major obstacle to further improvement of device performance. Here, a 2D/3D multidimensional structure formed spontaneously at room...