Effect of Heat Treatment on Electrical Properties and Charge Collection Efficiency of X-Ray Sensors Based on Chrome-Compensated Gallium Arsenide

Abstract

We present the results of experimental studies of the dependences of the specific resistance, charge collection efficiency, product of the mobility on the lifetime (μ×τ)_n, and current-voltage characteristics on the heat treatment regimes of X-ray Me–GaAs:Cr–Me-sensors. Experimental samples were the pad-sensors with the area of 0.1–0.25 cm² and sensitive-layer thickness in the range of 400-500 μm. The values of (μ×τ)_n were evaluated by measuring the dependence of the charge collection efficiency on the bias voltage when exposed to gamma rays from the source of 241Am. It is shown that heat treatment in the temperature range 200–500°C does not lead to a significant degradation of properties of Me–GaAs:Cr–Me-sensors and can be used in the manufacturing technology of matrix detectors of ionizing radiation.