Thermally activated electron conductivity in Ga(As,N) with N‐induced potential fluctuations

Abstract

The electron transport in Ga(As,N) layers is investigated focusing on the influence of potential fluctuations. A metal-insulator transition is observed with increasing electron concentration, in the temperature dependence of the resistivity for a series of samples with 0.8% and 1.7% of N. The observed behavior is discussed in the frame of Anderson transition. A quantitative value for the percolation threshold V p , at which the transport characteristics will change, is obtained by considering a chemical potential and an activation energy. The large V p can explain the thermally activated conductivity which can be observed even up to 300 K. We observe an increase of V p by increasing the N concentration up to 2.2%. Vp can be efficiently reduced by rapid thermal annealing for samples with higher N concentration.