Fig. 2: Characterization of room-temperature SPEs in β-Ga₂O₃.

Normalized confocal photoluminescence (PL) intensity maps of the homoepitaxial β-Ga₂O₃ (a) and heteroepitaxial β-Ga₂O₃ (b) films. Red boxes mark isolated emission points. c PL spectra fitted to Lorentzian functions for obtaining the individual weightage of zero-phonon line (ZPL) and phonon sideband (PSB) for both homoepitaxial and heteroepitaxial β-Ga₂O₃ films. The peaks marked by square grids and asterisks originate from the Raman mode of β-Ga₂O₃ and sapphire substrate, respectively. Second-order correlation functions g²(τ) of the single photon emitters (SPEs) from the homoepitaxial β-Ga₂O₃ (d) and the heteroepitaxial β-Ga₂O₃ (e) films measured under 5 mW continuous wave laser excitation. f Saturation behavior of the emission intensity of SPEs along with a theoretical fit for the homoepitaxial/heteroepitaxial β-Ga₂O₃ films.