Dual‐Phase Stabilized Perovskite Nanowires for Reduced Defects and Longer Carrier Lifetime

Abstract 1D perovskite materials are of significant interest to build a new class of nanostructures for electronic and optoelectronic applications. However, the study of colloidal perovskite nanowires (PNWs) lags far behind those of other established perovskite materials such as perovskite quantum dots and perovskite thin films. Herein, a dual‐phase passivation strategy to synthesize all‐inorganic PNWs with minimized surface defects is reported. The local phase transition from CsPbBr 3 to CsPb 2 Br 5 in PNWs increases the photoluminescence quantum yield, carrier lifetime, and water‐resistivity, owing to the energetic and chemical passivation effect. In addition, these dual‐phase PNWs are employed as an interfacial layer in perovskite solar cells (PSCs). The enhanced surface passivation results in an efficient carrier transfer in PSCs, which is a critical enabler to increase the power conversion efficiency (PCE) to 22.87%, while the device without PNWs exhibits a PCE of 20.74%. The proposed strategy provides a surface passivation platform in 1D perovskites, which can lead to the development of novel nanostructures for future optoelectronic devices.