Abstract
Abstract
In this study, we investigated the impact of strain on the electronic structure and polarization of Al
x
Ga1−x
N and AlGaN/GaN heterojunctions using first-principles density functional theory. Our findings reveal that, in the absence of strain, the band gap and electron effective mass of Al
x
Ga1−x
N increase with higher Al composition. Similarly, the spontaneous and piezoelectric polarization also increase accordingly. Moreover, under biaxial 5% tensile strain and 5% compressive strain, the two-dimensional (2D) electron gas surface density in the AlGaN/GaN heterojunction reaches 8.12 × 1012 cm−2 and 2.50 × 1012 cm−2, respectively. Comparatively, the surface density without strain is 5.62 × 1012 cm−2. Tensile strain significantly enhances the 2D electron gas surface density, which holds potential theoretical value for improving the electrical performance of AlGaN/GaN high electron mobility transistors.
Funder
National Natural Science Foundation of China
State Key Laboratory of Pulsed Power Laser Technology
Natural Science Basic Research Program of Shaanxi
Subject
Surfaces, Coatings and Films,Acoustics and Ultrasonics,Condensed Matter Physics,Electronic, Optical and Magnetic Materials