Phase Engineering for Stability of CsPbI 3 Nanowire Optoelectronics

Abstract Zinc (Zn) has arisen as a significant suppressor of vacancy formation in halide perovskites, establishing its pivotal role in defect engineering for these materials. Herein, the Zn‐catalyzed vapor‐liquid‐solid (VLS) route is reported to render black‐phase CsPbI 3 nanowires (NWs) operationally stable at room temperature. Based on first‐principle calculations, the doped Zn 2+ can not only lead to the partial crystal lattice distortion but also reduce the formation energy (absolute value) from the black phase to the yellow phase, improving the stability of the desired black‐phase CsPbI 3 NWs. A series of contrast tests further confirm the stabilization effect of the Zn‐doped strategy. Besides, the polarization‐sensitive characteristics of black‐phase CsPbI 3 NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI 3 NWs and their potential applications in anisotropic optoelectronics.