The question of optical bandgap anisotropy in the monoclinic semiconductor beta-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 beta-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 in the b onset is due to a suppression of the transition matrix elements of the three top valence bands at G point.

Theoretical and experimental investigation of optical absorption anisotropy in β-Ga2O3 / Ricci, F; Boschi, F; Baraldi, A; Filippetti, A; Higashiwaki, M; Kuramata, A; Fiorentini, V; Fornari, R. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 28:22(2016), p. 224005. [10.1088/0953-8984/28/22/224005]

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

BOSCHI, Francesco;BARALDI, Andrea;FORNARI, Roberto
2016

Abstract

The question of optical bandgap anisotropy in the monoclinic semiconductor beta-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 beta-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 in the b onset is due to a suppression of the transition matrix elements of the three top valence bands at G point.
Theoretical and experimental investigation of optical absorption anisotropy in β-Ga2O3 / Ricci, F; Boschi, F; Baraldi, A; Filippetti, A; Higashiwaki, M; Kuramata, A; Fiorentini, V; Fornari, R. - In: JOURNAL OF PHYSICS. CONDENSED MATTER. - ISSN 0953-8984. - 28:22(2016), p. 224005. [10.1088/0953-8984/28/22/224005]
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11381/2805680
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