Cadmium telluride thin-film detectors of nuclear radiation

Semiconductor detectors for X-ray and gamma radiation are developed based on thin cadmium telluride (p-n-CdTe) films possessing a columnar structure. The detector structures are formed on molybdenum substrates by CdTe sublimation and magnetron sputtering of cadmium. The p-CdTe films have a thickness of d = 30-150 mum and a resistivity of rho greater than or equal to 10(3)-10(7) Omega cm. The single crystal grains in the films have an average size of 50-100 mum and are oriented perpendicularly with respect to the Mo substrate. In comparison to the usual single crystal CdTe detectors, the proposed thin-film single crystal CdTe detectors possess a more perfect structure, since the grain boundaries act as effective sinks for defects. The energy resolution of the new generation of CdTe detectors reaches similar to5 keV for the 59.6 keV line of Am-241 at room temperature. (C) 2003 MAIK "Nauka/Interperiodica".