Low threshold room-temperature lasing emission from high-crystalline ZnS nanowires and nanobelts

Abstract

ZnS nanostructures possess exceptional features, making them highly promising as gain media and optical waveguides for nanolasers and optoelectronic devices. These features include low lasing thresholds and effortless fabrication. In this study, we present high-crystalline ZnS nanowires (NWs) and nanobelts (NBs) synthesized by using a thermal evaporation route. The remarkably low lasing thresholds of 45.3–45.5 W/cm2 are achieved at room temperature, marking a two-orders-of-magnitude improvement over reported values for ZnS nanostructures. Comprehensive analysis, incorporating techniques such as x-ray diffraction, Raman spectra, transmission electron microscopy, x-ray photoelectron spectroscopy, and photoluminescence, confirms the great quality of the synthesized nanostructures. The excitonic lasing emissions from ZnS NWs and NBs exhibit small full width at half maximum values of 5.9 and 0.53 nm, respectively. These emissions occur within cavities measuring ∼5.1 to 5.6 μm, with high-quality factors (112.6 for ZnS NWs and 598.6 for ZnS NBs), further highlighting the excellent performance of the materials. Moreover, the gain factors of 17.32–26.63 underscore the significant potential of ZnS NWs and NBs as prime candidates for ultraviolet photonic devices.