Simultaneous phase and luminescence control of CsPbX3 perovskite nanowires through Ca2+ doping

Abstract

Inorganic cesium lead halide (CsPbX3, X = Cl, Br, or I) perovskite nanowires (NWs) are promising materials for investigating charge transfer and carrier dynamics at the nanoscale level. However, the synthesis of CsPbX3 NWs with well-defined cubic phases and the desirable properties remains challenging. In this study, we successfully synthesized uniform-diameter cubic-phase CsPbBr3 NWs with favorable properties via trace Ca2+ doping. By combining experimental results with first-principles calculations, we confirmed that Ca2+ doping not only induces lattice distortion in cubic-phase CsPbBr3 nanocubes, triggering dipole moments that drive self-assembly into single-crystalline NWs via oriented attachment but also inhibits the formation of surface defects and significantly modulates the exciton relaxation kinetics by reducing nonradiative recombination, thus enhancing the photoluminescence efficiency and stability of perovskite NWs with high crystallinity. Furthermore, by exploiting the high plasticity of the CsPbX3 lattice, we demonstrated the ability to tune the composition and emission color of the NWs through anion exchange reactions while preserving their morphology and crystal structure. These findings provide a stable platform for preparing highly efficient perovskite materials with satisfactory optoelectronic properties for use in prospective photovoltaic and optoelectronic devices.