A method for adjusting the performances of epitaxial GaAs X-ray detectors

To detect high-energy photons using compound semiconductor detectors such as GaAs requires enlargement of the depleted zone, which is limited by the residual doping of the semiconductor. We discuss a technique by which the extension of the space charge region of a diode can be increased. It consists in compensating the residual doping impurities with defects introduced by electron irradiation. Results are presented to illustrate and evaluate the limits of this technique in the case of GaAs p/i/n structures.