Enhancing photoluminescence of monolayer MoS₂ on h-BN substrate through plasmonic resonance for high-power optoelectronic devices

Abstract Hexagonal boron nitride (h-BN) is an excellent substrate material due to its superb thermal conductivity, excellent thermal stability and smooth surface qualities. In this study, a silicon-based h-BN substrate was prepared using the magnetron sputtering technique. Subsequently, monolayer MoS 2 obtained by the CVD method was transferred onto the h-BN substrate. Then, Au-core-Ag-shell nanoparticles with a diameter of 80 nm were prepared by a self-assembly method and uniformly dispersed and spin-coated on the MoS 2 surface. Applying a laser with a wavelength of 532 nm can effectively excite the plasma resonance effect of the system. Under the intense thermal effect induced by the high laser power and plasma effect, the h-BN substrate ensures that MoS 2 exhibits less red-shift and higher photoluminescence intensity compared with SiO 2 substrate due to its excellent thermal conductivity. This means that h-BN substrates are particularly suitable for optoelectronic applications under high laser power environments, and can maintain excellent optoelectronic device performance while effectively curbing overheating to ensure long-term stable device operation.