Evolution of the impurity band in a weakly doped, highly compensated semiconductor

Abstract

We study the evolution of the impurity band in a weakly doped semiconductor as a function of the concentration of dopants, x. We present disorder-averaged results for the density of states of a doped simple cubic lattice and compare them with the predictions of the coherent potential approximation (CPA). For randomly distributed impurities the agreement is good, although CPA misses some qualitative features. We find that if electron-electron interactions can be ignored, as is the case in the highly compensated limit, the impurity band is still a clearly distinct feature in the spectrum even for dopant concentrations as large as x ∼ 0.10.

The structure of heavily doped impurity band in crystalline host

“…As increasing the concentration x, the overlap between different impurity states extends the single impurity energy to an impurity band in the density of state (DOS) and eventually merges with the conductance band. Simultaneously, the states in the impurity band are expected to become more and more extended and ultimately regain their bandlike character [5]. However, the details inside the impurity band are rarely * Electronic address: zxhu@cqu.edu.cn studied.…”

Machine learning and high-performance computing in numerical simulation of quantum many-body systems

“…According to Ref. [51], while the doping concentration x > 5%, the maximum height and broad of the impurity band DOS seems to saturate thus we treat 5% as the typical value of the heavy doping concentration. As shown in Fig.…”

“…As the concentration x increases, the overlap between different impurity states extends the single impurity energy to an impurity band in the density of state (DOS) and eventually merges with the conductance band. Simultaneously, the states in the impurity band are expected to become more and more extended and ultimately regain their bandlike character [51].…”