High‐temperature electrical properties of CdTe:Bi single crystals

Abstract

At first the experimental results of detailed Hall effect measurements at high‐temperature defect equilibrium under Cd/Te vapor pressure in CdTe single crystals were obtained. They indicate that at these conditions Bi forms in CdTe crystals mainly BiCd donor centers. The analysis of the free electron density temperature dependencies allows to conclude that up to 800 K the electrons of dopant atoms define the sample's electrical properties. The native donor point defects begin to influence the electro‐neutrality condition above this temperature. The research of high‐temperature electrical properties of Bi‐doped CdTe samples shows that the real electrical active Bi content in the investigated crystals is ∼1017 at/cm3. The electron density dependencies vs PCd, modeled at constant temperatures (500‐900°C), in the assumption of deep Bi donor (EV+0.71 eV) are in good agreement with experiment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)