Photoinduced Ions Migration to Brighten Perovskite Nanowires on Glass

Mixed-halide perovskite nanostructures possess widely-tunable optical and electronic properties that are desirable for applications in optics and optoelectronics, such as photodetectors, micro-LEDs, photovoltaics and lasers. Photoinducing phase segregation often occur on these nanostructures with halide ions, e.g., iodide ions, migrating away from the original mixed-halide crystal lattice, which impairs their photoluminescence (PL) properties and impedes the integrated applications. Herein, significant photoinduced PL enhancement is reported with a PL shift from green to red on the Br-I halides-containing perovskite nanowires (NWs). This is proposed to be caused by the formation of Br-I mixed phase due to the migration and incorporation of iodide ions into the deficient-rich CsPbBr 3 lattice within the NWs. It is demonstrated that this principle is general to regulate the PL on NWs with various halide compositions. Optoelectronic applications in waveguiding and short-time optical storage are exploited experimentally. This work provides new insights into the photoinduced PL modulation, which would advance and expand the optoelectronic applications.