Investigation of the interface characteristics of Y2O3/GaAs under biaxial strain, triaxial strain, and non-strain conditions

Abstract

We investigate the interface behaviors of Y2O3/GaAs under biaxial strain, triaxial strain, and non-strain conditions. This study is performed by first principles calculations based on density functional theory (DFT). First of all, the biaxial strain is realized by changing the lattice constants in ab plane. Averaged electrostatic potential (AEP) is aligned by establishing Y2O3 and GaAs (110) surfaces. The band offsets of Y2O3/GaAs interface under biaxial strain are investigated by generalized gradient approximation and Heyd–Scuseria–Ernzerhof (HSE) functionals. The interface under biaxial strain is suitable for the design of metal oxide semiconductor (MOS) devices because the valence band offsets (VBO) and conduction band offsets (CBO) are larger than 1 eV. Second, the triaxial strain is applied to Y2O3/GaAs interface by synchronously changing the lattice constants in a, b, and c axis. The band gaps of Y2O3 and GaAs under triaxial strain are investigated by HSE functional. We compare the VBO and CBO under triaxial strain with those under biaxial strain. Third, in the absence of lattice strain, the formation energies, charge state switching levels, and migration barriers of native defects in Y2O3 are assessed. We investigate how they will affect the MOS device performance. It is found that VO+2 and Oi−2 play a very dangerous role in MOS devices. Finally, a direct tunneling leakage current model is established. The model is used to analyze current and voltage characteristics of the metal/Y2O3/GaAs.

First principles calculations of the interface properties of a-Al2O3/MoS2 and effects of biaxial strain

“…For MoS 2 surface, the planar AEP in the atomic region exhibits a periodic oscillation, while it remains constant in the vacuum region. 67 It is found that the shape of planar AEP do not change as the number of the MoS 2 layers changes from 1 to 6. For aAl 2 O 3 surface, the planar AEP in the atomic region has no obvious periodicity.…”

Interface spacing, stability, band offsets, and electronic properties on a (001) SrHfO3/GaAs interface: First-principles calculations

“…It is noted that the interface spacing affects the band offsets, resulting in deviation between theoretical calculation and experiment. [55][56][57][58] The layer electronic density of states for SrO/Ga(1) and HfO 2 /Ga(2) is presented in Fig.6. The chemical formula of symmetric slab is Hf 20 Sr 24 O 64 /Ga 36 As 32 for SrO/Ga (1) and Hf 24 Sr 20 O 68 /Ga 36 As 32 for HfO 2 /Ga(2).…”

“…It is noted that the interface spacing affects the band offsets, resulting in deviation between theoretical calculation and experiment. [55][56][57][58] The layer electronic density of states for SrO/Ga(1) and HfO 2 /Ga(2) is presented in Fig. 6.…”

First principles investigation of nitrogenated holey graphene

“…The charge states of these defects are mainly determined by +1, -1, and The result shows that the defects act as carrier traps. In addition, charge defects also lead to region of fixed charge that can scatter carrier and shift the threshold voltage of the device [39].…”