Optical sensing of organic solvents vapor with lead halide perovskite nanowire lasers on one-dimensional polymer nanograting

Timely detection of organic solvent vapors at their low concentrations is an urgent problem of the chemical industry. Various optical applications attempt to solve it, facing the challenges of low sensitivity and costly high-tech production. This work presents the design of the sensitive optical detector based on the CsPbBr₃ perovskite nanowire (NW) laser deposited on a polystyrene (PS) periodic structure responsive to organic solvent presence. Molecules of solvents are effectively absorbed by PS nanograting leading to the reshaping of the last. Enlargement of the PS nanograting acting as a substrate for CsPbBr₃ nanolaser causes a change in the effective refractive index of the medium under perovskite cavity. High-quality lasing modes of the perovskite cavity respond to this change via undergoing the spectral shift. Numerical modeling reveals the sufficient redshift of 0.15 nm in response to the 5 nm increase of PS nanograting ridges. We show that the sensitivity of lasing mode depends on its order which strongly correlates with the field confinement. These results might be useful for further progress in perovskite-based optical gas sensing.