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

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 of the b onset is due to a suppression of the transition matrix elements of the three top valence bands at $\Gamma$ point.

arXiv comment11 pages, 5 figures

References in corpus (2)

• A variational pseudo-self-interaction correction approach: ab-initio description of correlated oxides and molecules
• Multi-gap absorption in CaCu${}_3$Ti${}_4$O${}_{12}$ and the predictivity of ab initio methods

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