Programme

O.7 -- Oral, VCTP-45

Date: Monday, 12 October 2020

Time: 14:50 - 15:10

Defects Studies in beta-Ga2O3 Using an Optimized Hybrid Functional

Quoc Duy Ho

Can Tho University of Technology

Monoclinic gallium oxide (beta-Ga2O3) has recently attracted a lot of attention due to its unique properties. Beta-Ga2O3 is a wide band gap semiconductor, a lot of deep defect levels can be present in the gap state. Although, recently, on beta-Ga2O3 more scientific results have been published, due to the appearance of new experimental technologies, there is still little known about beta-Ga2O3. Density functional theory (DFT) with hybrid exchange, so-called hybrid functional (HSE), with two parameters ($\alpha$ and $\mu$) can be tuned to reproduce the experimental band gap and fulfill the generalized Koopman’s theorem. Peter Deak, Quoc Duy Ho et al. [Phys.Rev. B 95, 075208 (2017)] has tuned both $\alpha$ and $\mu$ and found that the hybrid functional with the parameters $\alpha = 0.26$ and $\mu = 0.00$ is the optimal HSE for beta-Ga2O3 defects studies. This optimized hybrid functional, HSE(0.26,0.00), satisfies the generalized Koopman’s theorem and can reproduce the whole GW band structure accurately. In this research, HSE(0.26,0.00) is utilized to study transition levels, origins of luminescence and hyperfine interaction of defects in beta-Ga2O3.

Presenter: Ho Quoc Duy