Determination of subband energies and 2DEG characteristics of AlxGa1−xN/GaN heterojunctions using variational method

Abstract

A physics-based model based on the variational method for analyzing the two dimensional electron gas (2DEG) characteristics of polar AlGaN/GaN heterojunctions is developed. The 2DEG carrier concentration, the first and second energy subbands, and the position of the Fermi energy level are calculated for various barrier thicknesses, Al mole fractions, background dopant concentrations, and gate voltages for gated AlGaN/GaN heterojunctions. The results are in good agreement with the data reported based on self-consistent method. Whereas the aforementioned report has dealt with specific values of Al mole fraction, barrier thickness, and unintentional doping level, the present work provides a basis for calculating the 2DEG characteristics for the full range of these parameters. Furthermore, according to the proposed model, the applicability of the triangular approximation of the quantum well in AlGaN/GaN heterojunctions is evaluated.

Dependence of spin dynamics on in-plane magnetic field in AlGaN/GaN quantum wells

“…Therefore, it is reasonable to expect that the WAL of Sample 1 (Sample 2) is dominated by the k-linear BIA (SIA) SOI, respectively. In contrast to the single subband occupancy for Sample 1, the second subband is considered to be occupied for Sample 2 due to the high density [23]. Assuming the presence of strong intersubband scattering, the subbands will be coupled and mixed up, and electrons will behave as if they were in a one subband with an average kinetic parameter [24][25][26].…”

“…Assuming the presence of strong intersubband scattering, the subbands will be coupled and mixed up, and electrons will behave as if they were in a one subband with an average kinetic parameter [24][25][26]. In addition, the electron density of the second subband is much smaller than that of the first subband because the second subband energy level is much closer to the Fermi level [23,27], and its influence is relatively weak. Therefore, we may treat the WAL effect in Sample 2 with a single subband occupied for simplicity.…”