Detectors of Gamma Rays and Alpha Particles Based on Ta-Doped InP Converted to the Semi-Insulating State by Annealing

InP crystals were synthesized with a Ta admixture grown by the Czochralski technique, and wafers cut from the grown crystals were converted to the SI state by high-temperature annealing. The good detection performance of such material-based detectors has been tested with alpha-particles from a ²⁴¹Am source (5.48 MeV). The charge collection efficiency (CCE) of 84% and relative energy resolution at full width at half maximum (FWHM) of 5% were obtained at room temperature 295 K (RT). Low-energy gamma-photons of 122 keV from a ⁵⁷Co source and gamma-photons from a ¹³⁷Cs source were detected at 242 K, 272 K, and 295 K, respectively. The values of CCE 88% and FWHM 16 keV of 122 keV photons and CCE 87% and FWHM 48 keV of gamma-photons of 662 keV were obtained at reduced temperatures. A pulse-height spectrum of 662 keV gamma-photons registered at room temperature is also shown in this work.