Methods of Charge-Carrier Mobility Measurements in Structures Based on High-Resistivity Gallium Arsenide with Deep Centers

One of the most important parameters determining the efficiency of X-ray sensors is the μ∙τ product, where μ is the charge-carrier mobility and τ is the carrier lifetime. This paper presents results of measurements of the charge-carrier mobility in high-resistivity (HR) GaAs:Cr sensors using two methods: the laser-induced transient-current technique (LTCT) and the Hall measurements. It has been found that the concentration of holes in the HR GaAs:Cr material exceeds that of electrons, whereas the value of the electron drift mobility is in the range 4000–4300 cm 2 /(V·s).