Phase Engineering for Stability of CsPbI3 Nanowire Optoelectronics.

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 CsPbI3 nanowires (NWs) operationally stable at room temperature. Based on first‐principle calculations, the doped Zn2+ 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 CsPbI3 NWs. A series of contrast tests further confirm the stabilization effect of the Zn‐doped strategy. Besides, the polarization‐sensitive characteristics of black‐phase CsPbI3 NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI3 NWs and their potential applications in anisotropic optoelectronics. [ABSTRACT FROM AUTHOR]