Optical Properties and Nanocavity Response of CsPbCl ₃ Nanowires: Implications for Light-Emitting Devices

Advanced photochemical stability, excellent lasing response, and multifold higher nonlinear optical magnitude of all-inorganic CsPbX3 (X = Cl, Br, and I) perovskites made them superior to their organic–inorganic hybrid halide counterparts and other conventional semiconducting materials. Herein, in addition to basic material properties, various aspects of the photoluminescence (PL) behaviors along with the highest ever Q-factor nanocavity response of CsPbX3 (X = Cl) perovskite nanowires (NWs) are reported. The high-quality, single-crystalline CsPbCl3 NWs were grown by the noncatalytic chemical vapor deposition (NC–CVD) approach. Strong violet-blue (∼415 nm) PL emission, excellent response to multiphoton absorption (MPA), and harmonic generation suggest that these NWs are suitable for light manipulation and detection-related miniaturized device applications. Temperature- and power-dependent PL measurements reveal that the PL emissions from the CsPbCl3 NWs originate from excitonic transitions. Further, excitation fluence-dependent PL measurements on typical CsPbCl3 NW demonstrate excellent single-mode lasing at PTh ∼ 130 μJ/cm2 with a nanocavity response quality factor, Q ∼ 4500, higher than most reported values for similar materials and nanostructures. We believe that, in addition to device miniaturization, these findings will surely advance and promote the one- and multiphoton absorption (OPA and MPA)-related optoelectronic applications of CsPbX3 perovskites. Moreover, the insights of the photophysical transitions revealed here for large bandgap (Eg ∼ 2.99 eV) CsPbCl3 NWs may also facilitate the understanding of the photophysics of other wide bandgap semiconductors.