CdTe crystals, doped by Cl, are widely used for γ-detectors manufacturing due to their high resistivity and atomic number, as well as long carriers lifetime. Up to now, their properties were investigated in details only at rather low temperatures. It is of interest to know the point defect structure of this material at high temperature where it forms, what will allow to govern the type and concentration of point defects.
CdTe<Cl> crystals were grown by THM and traditional Bridgman techniques. High temperature Hall effect measurements were carried out under well defined Cd or Te vapor pressure in temperature ranging from 300 to 900^o C in sealed quartz ampoule using graphite contacts.
At room temperature all of them revealed high resistivity (ρ>10⁸ Ohm cm) with hole mobility ~60 cm²/Vs.
In the investigated samples, the electron mobility decreases from ~500 V/cm²s at 400^oC to ~170 V/cm²s at 900^o C. During the first heating up to T=650^oC the electron concentration did not depend on temperature or Cd pressure and was 5x10¹⁸ cm^-3; it rises at higher temperatures only. After a quick cooling a rise of [e^-] by 1,5-2 times comparing with initial level is observed. A similar situation is reported during the second and third heating-cooling cycle.
Under Te vapor pressure the samples demonstrated p-type conductivity from 180C(μ = 30 V/cm²s, [h+]=10¹⁶ cm^-3) up to (μ =5 V/cm²s, [h+]=3x10¹⁷ cm^-3). Between T=550-800^oC the conductivity was bipolar and only for even high values (T>800^oC) the mobility becomes really of n-type.
In this paper, the observed phenomena are explained in terms of point defect chemistry by Cl-containing precipitates dissolution in Cd saturation region and by rising both Te_i^- and V_Cd^- concentrations in the Te region.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/1818 must be provided.

1. Electrical properties of CdTe:Br single crystals at high temperature
2. Recent initiatives to create a materials community in Europe
3. Self-compensation processes in CdTe<In> single crystals
4. High-temperature electrical properties of CdTe<Pb> crystals under Te saturation
5. Applications of the II-VI semimagnetic semiconductors
6. Is the (Cd,Mn)Te crystal a prospective material for X-ray and γ-ray detectors?
7. Security control by an innovative X-ray method
8. Applying advanced solid-state radiation detector technologies for public protection
9. Laser stimulated p-n junction formation in CdTe
10. Nanocrystals of CdTe and CdMnTe: Growth, Optical and Magnetooptical Properties