Ail Indium (In) doped Cd0.9Zn0.1Te (CdZnTe:In) ingot was grown by vertical Bridgman method. The distribution of In in the ingot was analyzed. It was evaluated that the segregation Coefficient of In in CdZnTe during the growth was 1.3. which caused a hi-her In concentration in the initial part of CdZnTe:In ingot and a lower Ill concentration in the final part. Ill was also enriched at the grain boundaries but homogenously distributed inside the grains in the as-grown crystal. Photoluminescence spectra indicated that Ill had two states existing In the CdZnTe:In ingot. One was interstitial neutral In and the other was substitutional ion In+. The two states led to the two donor levels at 0.12 and 0.04 eV ill CdZnTe:In band construction, respectively. IR transmission measurements exhibited that CdZnTe:In was almost opaque to IR emission when the wavenumber was larger than 1000 cm(-1) then was 24% transparent when the wavenumber was decreased to lower than 1000 cm(-1). This phenomenon also confirmed the existence of the donor level of 0.12 eV demonstrated by the PL spectra. Resistivity measurements revealed that CdZnTe:In obtained three orders higher resistivity than CdZnTe. It meant that doping, of In into CdZnTe could improve the crystal properties. (C) 2004 Elsevier B.V. All rights reserved.