Point defect structure of CdTe〈Cl〉 crystals at high temperatures



High temperature Hall effect measurements in CdTe〈Cl〉 single crystals grown by THM and Bridgman techniques at 200–900 °C under well defined Cd and Te vapor pressure were made. Associates decay at heating from 500 to 700 °C in THM grown samples was observed. Cd vapour pressure influence on electron concentration [e] in all samples was established. The main point defects present in crystals were: at T < 600 °C - chlorine donors and chlorine associates, at T > 700 °C - chlorine donors, Cd vacancies and Cd interstitials. Bridgman grown CdTe〈Cl〉 crystals had [e] similar to undoped CdTe and differed in Cd vapor pressure dependencies by line slopes. Under Te vapor pressure the samples demonstrated p-type conductivity up to 550 °C. In this case the hole density changed from [h+] = 1016 cm–3 to 3 × 1017 cm–3 and did not depend on Te vapor pressure. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)