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arXiv · 1511.02601

Theoretical and experimental investigation of optical absorption anisotropy in $β$-Ga2O3

Francesco Ricci·Francesco Boschi·Andrea Baraldi·Alessio Filippetti·M. Higashiwaki·A. Kuramata·Vincenzo Fiorentini·Roberto Fornari
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Abstract

The question of optical bandgap anisotropy in the monoclinic semiconductor $β$-Ga2O3 was revisited by combining accurate optical absorption measurements with theoretical analysis, performed using different advanced computation methods. As expected, the bandgap edge of bulk $β$-Ga2O3 was found to be a function of light polarization and crystal orientation, with the lowest onset occurring at polarization in the ac crystal plane around 4.5-4.6 eV; polarization along b unambiguously shifts the onset up by 0.2 eV. The theoretical analysis clearly indicates that the shift of the b onset is due to a suppression of the transition matrix elements of the three top valence bands at $Γ$ point.

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Francesco Ricci, Francesco Boschi, Andrea Baraldi, Alessio Filippetti, M. Higashiwaki, A. Kuramata, Vincenzo Fiorentini, Roberto Fornari. 2015-11-09. Theoretical and experimental investigation of optical absorption anisotropy in $β$-Ga2O3. https://doi.org/10.1088/0953-8984%2F28%2F22%2F224005

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