Journal of Alloys and Compounds 371 (2004) 118–121 Vapour pressure investigation of CdZnTe V.N. Guskov a , J.H. Greenberg b,∗ , M. Fiederle c , K.-W. Benz c a Institute of General and Inorganic Chemistry RAS, Leninsky pr., 31, 119991 Moscow, Russia b Department of Inorganic Chemistry, Hebrew University, 91904 Jerusalem, Israel c Albert-Ludwigs Universitat, Hebelstr. 25, Freiburg D-79104, Germany Received 14 October 2002; received in revised form 24 June 2003; accepted 26 June 2003 Abstract Vapour pressure measurement in the Cd–Zn–Te system is reported for T = 700–1300 K and P ≤ 760 mm Hg. From the experimental data for x = 0.05, 0.10, 0.15, 0.25, 0.5, 0.75, 0.80, 0.90 and 1.0, complete P–T projection of the phase diagram for the quasi-binary Cd 1−x Zn x Te system has been constructed. Transformation of the P–T projection was traced for the whole range of the Cd 1−x Zn x Te solid solution as a function of the ZnTe concentration. From detailed studies of sections x = 0.05, 0.1, 0.15 and 1.0, maximum non-stoichiometry as a function of temperature was determined both for Te and metal solubility. For ZnTe the solidus volume is on the Te side of the stoichiometric plane (50 at.% Te). Zn-boundary of ZnTe solidus is 50.004–50.005 at.% Te in composition at 826–1153 K. Formation of the Cd 1−x Zn x Te solid solution leads to extension of the homogeneity range, especially at high temperatures. Increase of ZnTe content in the solid solution results in a shift of the solidus toward Te, so that already for x = 0.15 the solidus does not contain the stoichiometric plane. © 2003 Elsevier B.V. All rights reserved. PACS: 81.05.Dz; 81.30.Bx; 82.60.Lf Keywords: Semiconductors; Gas-solid reactions 1. Introduction CdTe and Cd 1−x Zn x Te are promising materials for ap- plications as substrates for IR detectors, photorefractive devices, X-ray and -ray detectors. A common requirement for these applications is the need of high quality single crys- tals. Meanwhile, growth of single crystals with controlled stoichiometry still poses a grave technological problem. The knowledge of the pressure–temperature–composition (P–T–X) phase equilibrium gives the thermodynamic basis for the crystal growth of materials with controlled composi- tion. Detailed study of the P–T–X phase diagram for Cd–Te system and vapour pressure scanning of non-stoichiometry in CdTe has been reported in [1,2]. Results of the vapour pressure measurement and estimates of solubility of the components in ZnTe were presented in [3,4]. Recently [5,6] thermodynamic properties of ZnTe were updated by experimental measurement of low- and high-temperature ∗ Corresponding author. Tel.: +972-2-6586-174; fax: +972-2-6586-319. E-mail address: jacob.greenberg@huji.ac.il (J.H. Greenberg). heat capacity. For the ternary Cd–Zn–Te, only a condensed phase diagram has been studied in detail [7]. Knudsen cell mass spectrometry was applied to study the quasi-binary CdTe–ZnTe system at T = 900 K [8]. P–X isothermal sec- tion was constructed and thermodynamic properties of the solid solution were determined. This paper reports results of the first direct vapour pres- sure measurement in the ternary system Cd–Zn–Te at tem- peratures 700–1350 K and pressures up to 760 mm Hg. On this basis, P–T projection of the diagram was constructed and maximum non-stoichiometry was estimated for the Cd 1−x Zn x Te solid solution with x ≤ 0.15. 2. Results and discussion Preparation of the samples and vapour pressure measure- ment procedure was described in detail elsewhere [1–4]. Special attention was paid to ensure equilibrium conditions for the experiment. Vapour pressure was measured in the following way. A slightly sub-stoichiometric sample (less then 50 at.% Te in composition) with a fixed atomic Cd:Zn 0925-8388/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2003.06.013