We report the strain and stress relationships for the three lowest energy direct band to band transitions at the Brillouin zone center in monoclinic beta-Ga2O3. These relationships augment four linear perturbation parameters for situations, which maintain the monoclinic symmetry, which are reported here as numerical values obtained from density functional theory calculations. With knowledge of these perturbation parameters, the shift of each of the three lowest band to band transition energies can be predicted from the knowledge of the specific state of strain or stress, thus providing a useful tool for modeling performance of power electronic devices and rational strain engineering in heteroepitaxy.
Funding Agencies|National Science Foundation (NSF)National Science Foundation (NSF) [NSF DMR 1808715]; Emergent Quantum Materials and Technologies (EQUATE) [OIA-2044049]; Air Force Office of Scientific ResearchUnited States Department of DefenseAir Force Office of Scientific Research (AFOSR) [FA9550-18-1-0360, FA9550-19-S-0003, FA9550-21-1-0259]; Knut and Alice Wallenbergs FoundationKnut & Alice Wallenberg Foundation; University of Nebraska Foundation; J. A. Woollam Foundation; Swedish Research CouncilSwedish Research CouncilEuropean Commission [2016-00889]; Swedish Foundation for Strategic ResearchSwedish Foundation for Strategic Research [RIF14-055, EM16-0024]; Swedish Governmental Agency for Innovation Systems VINNOVA under the Competence Center Program [2016-05190]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link_oping University [2009-00971]; Nebraska Research Initiative