Degradation of Ga2Se2 grown by Molecular Beam Epitaxy

• Hien Huynh, Material Science, Villanova University

• Matthew Doty, Department of Materials Science and Engineering, University of Delaware

 Quantum emitters are devices that emit one and only one photon per excitation cycle. Such control over single photon emission is important for emerging quantum device opportunities including sensing, computing, and secure information transmission. Gallium Selenide (Ga2Se2), with thickness-dependent bandgap enabling integration with a variety of photonic device technologies, is a promising 2D material for quantum emitter applications. This study investigates the degradation of Ga2Se2 flakes exfoliated from Ga2Se2 films grown on GaAs substrates using Molecular Beam Epitaxy (MBE). The degradation process was monitored over a 24-hour period using Photoluminescence (PL) spectroscopy. Unlike bulk Ga2Se2‘s gradual intensity decline, MBE-grown samples exhibited fluctuating spectral intensity over time rather than consistent degradation. Subsequent spectral surface mapping of the flakes revealed that non-uniformity in the Ga2Se2 flake surfaces, coupled with positional variations in spectrometer measurements, contributed to the observed inconsistencies in spectral data.