Study on the performance of SI-GaAs and SI-InP surface barrier detectors for alpha and gamma detection

Undoped semi-insulating gallium arsenide and iron (Fe)-doped indium phosphide radiation detectors have been fabricated. The electrical characteristics (I–V and C–V) of the detectors have been carried out at room temperature under dark conditions. By analysing the I–V characteristics of the detectors, the barrier height, ideality factor and reverse leakage current have been evaluated. The SI-GaAs detector has been tested using 241Am alpha particle source of 5.48 MeV energy under a vacuum of 1×10−3 Torr at room temperature. An alpha energy resolution of 6% has been obtained. The detector charge collection efficiency was measured using the source and was found to be 98%. The SI-InP detector has been tested using 57Co(122 keV) and 137Cs (662 keV) gamma sources and the energy response of the InP detector has been analysed. In this article, details on the performance of our SI-GaAs and SI-InP surface barrier detectors for alpha- and gamma-ray detection are presented.