Analysis of In and Al doped high resistivity CdZnTe crystal

In this paper, the vertical Bridgman method was used to grow In-doped, Al-doped and In-Al codoped CdZnTe crystals. The temperature-dependent Hall effects, X-ray diffraction (XRD), dislocation density were applied to study the energy level of chief defects and the possible existence of compensatory mechanism in the doped CdZnTe crystal. The XRD results showed that lattice distortion existed in the three doped samples, and the lattice distortion in Al-doped crystal was the highest among them. The phenomenon may attribute to the stress caused by the occupation of In and Al atoms at Cd vacancies which make atoms depart from their equilibrium positions. The Hall effect test showed that the n-type In doped CdZnTe samples were estimated to have shallow donors at 15.6 meV below the conduction band, which is associated with [InCd], and the In-Al codoped samples have shallow donors at 15.1 meV below the conduction band, which is associated with [InCd]and [AlCd]. While, for the p-type Al doped CdZnTe sample, shallow acceptors were deduced at 59.9 meV above the valence band, which is considered to be [VCd-2AlCd] (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)