Temperature dependence of carrier mobility in undoped and gadolinium-doped p-GaSe crystals

Abstract

We have studied the temperature dependence of carrier mobility (μ) in undoped and gadolinium-doped p-GaSe crystals. The results demonstrate that, in the temperature range 77–420 K, the carrier mobility in high-resistivity p-GaSe〈Gd〉 crystals increases at low temperatures as a power law. At high temperatures, μ(T) has a maximum and varies roughly as \(T^{ - \tfrac{3} {2}} \). In addition, μ is a nonmonotonic function of gadolinium content. The observed anomalies in the temperature dependence of carrier mobility in the crystals studied are due to partial disorder in these materials. The present experimental data can be interpreted in terms of a two-barrier energy-band model of partially disordered semiconductors.