Incident wavelength and polarization dependence of spectral shifts in β-Ga₂O₃ UV photoluminescence.

ABSTRACT: We report polarization dependent photoluminescence studies on unintentionally-, Mg-, and Ca-doped β-Ga₂O₃ bulk crystals grown by the Czochralski method. In particular, we observe a wavelength shift of the highest-energy UV emission which is dependent on the pump photon energy and polarization. For 240 nm (5.17 eV) excitation almost no shift of the UV emission is observed between E||b and E||c, while a shift of the UV emission centroid is clearly observed for 266 nm (4.66 eV), a photon energy lying between the band absorption onsets for the two polarizations. These results are consistent with UV emission originating from transitions between conduction band electrons and two differentially-populated self-trapped hole (STH) states. Calcuations based on hybrid and self-in

SUBMITTER: Wang Y 

PROVIDER: S-EPMC6305385 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature