Development of nuclear radiation detectors with energy resolution capability based on CdTe-n/sup +/-GaAs heterojunction diodes

CdTe-n/sup +/-GaAs heterojunction diodes for room-temperature nuclear radiation detectors have been developed and demonstrated. The heterojunction diode was fabricated by growing a thin n-type CdTe buffer layer followed by the undoped p-like CdTe layer of about a 100 μm thickness on the n/sup +/-GaAs substrates using metal-organic vapor phase epitaxy. The diode detectors exhibited good rectification property and had the reverse leakage currents of a few μA/cm² at 40 V bias. The detector clearly demonstrated its energy resolution capability by resolving the 59.54 keV gamma peak from the /sup 241/Am radioisotope during the radiation detection test.