Title

Low temperature, postgrowth self-doping of CdTe single crystals due to controlled deviation from stoichiometry

Authors

Authors

V. Lyahovitskaya; L. Chernyak; J. Greenberg; L. Kaplan;D. Cahen

Comments

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Abbreviated Journal Title

J. Appl. Phys.

Keywords

CADMIUM TELLURIDE; NONSTOICHIOMETRY; PHASE; GROWTH; Physics, Applied

Abstract

Careful analysis of the Cd-Te pressure-temperature-composition phase diagram, shows a deviation of CdTe stoichiometry only in the Te-depletion direction between 450 and 550 degrees C. Combined control over the semiconductor composition, via intrinsic defects, and over the atmosphere and cooling rate can, therefore, yield a process for intrinsic doping of CdTe at these relatively low temperatures. We present results that support this. Quenching of CdTe, following its annealing in Te atmosphere at 400-550 degrees C, leads to p-type conductivity with a hole concentration of similar to 2 x 10(16) cm(-3). Slow cooling of the samples, after 550 degrees C annealing in Te or in vacuum, increases the hole concentration by one order of magnitude, as compared to quenching at the same temperature. We explain this increase by the defect reaction between Te vacancies and Te interstitials. Annealing in Cd at 400-550 degrees C leads to n-type conductivity with an electron concentration of similar to 2 x 10(16) cm(-3). Annealing at 450-550 degrees C in the equilibrium atmosphere, provided by adding CdTe powder, gives n-type material. (C) 2000 American Institute of Physics. [S0021-8979(00)05120-3].

Journal Title

Journal of Applied Physics

Volume

88

Issue/Number

7

Publication Date

1-1-2000

Document Type

Article

Language

English

First Page

3976

Last Page

3981

WOS Identifier

WOS:000089371600024

ISSN

0021-8979

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