High‐Performance Perovskite Photovoltaics by Heterovalent Substituted Mixed Perovskites

Abstract 2D perovskites are relatively stable but possess poor charge transport compared to 3D perovskites. To boost charge transport, novel 2D perovskites mixed with 3D perovskites are developed, where Pb 2+ are partially substituted by the heterovalent neodymium cations (Nd 3+ ) within both 2D and 3D perovskites (termed Nd 3+ ‐substituted 2D:3D mixed perovskites. Systematical studies reveal that the Nd 3+ ‐substituted 2D:3D mixed perovskites possess larger crystals, superior crystallinity, suppressed non‐radiative charge recombination, and enhanced and balanced charge transport compared to the 2D:3D mixed perovskites. As a result, perovskite photovoltaics based on the Nd 3+ ‐substituted 2D:3D mixed perovskites exhibit a power conversion efficiency of 22.11%, a photoresponsibility of over 700 mA W −1 , a photodetectivity of 4.29 × 10 14 cm Hz 1/2 W −1 , a linear dynamic range of 165 dB at room temperature, and dramatically boosted stability. These results demonstrate that, a facile way is developed to realize high‐performance perovskite photovoltaics through partially heterovalent substituted Pb 2+ by Nd 3+ within 2D:3D mixed perovskites.