Temperature-dependent Raman-active phonon modes and electron-phonon coupling in -Ga₂O₃ microwire

The lattice vibration and electron-phonon coupling (EPC) in beta-Ga2O3 microwire are systematically investigated. The beta-Ga2O3 microwire that is (020)-oriented shows 14 Raman peaks, with all their FWHM narrower than those of (100)-oriented beta-Ga2O3 bulk single crystal. As the temperature increases from 80 to 300 K, most Raman-active phonon modes are blueshifted, while a few modes are first blueshifted and then redshifted. The photoluminescence mainly originates from the recombination of self-trapping exciton and the quantitative analysis reveals that there exists quite strong EPC in beta-Ga2O3 microwire and the Huang-Rhys factor is up to S' approximate to 14. (c) 2024 The Author(s). Published on behalf of The Japan Society of Applied Physics by IOP Publishing Ltd