Evaluation of deep-impurity governed photoelectrical properties in differently doped CdTe

Autor: Kestutis Jarasiunas, M. Sudzius, A. Kadys, P. M. Fochuk, D. Verstraeten, M. L. Hellin, P. Feychuk
Rok vydání: 2007
Předmět:
Zdroj: physica status solidi (b). 244:1675-1679
ISSN: 1521-3951
0370-1972
DOI: 10.1002/pssb.200675149
Popis: We investigated nonequilibrium carrier generation, transport, and recombination processes in differently doped bulk CdTe crystals by the contactless nonlinear optical technique - the degenerate four-wave mixing. Doping by Ge, Pb, Sb, Se, Si, or Sn was reached by Bridgman, whereas vanadium doped CdTe ingots were grown by the vertical Bridgman-Stockbarger method. Some crystals of CdTe: Sb as well as CdTe: Ge were cut from the different parts of ingots. At 1064 nm below bandgap excitation by light interference pattern and varying the grating period, we measured the space-charge field dependent values of effective diffusion coefficient and determined a sign of the photogenerated carriers. In samples, doped with V, Sb, Si, or Ge, the experiments revealed that the majority carriers are electrons, while in Pb, Se, Sb, Ge, or Sn-doped crystals - the holes. Strong feed-back effect of the light-created SC electric field to subnanosecond carrier dynamics was observed in the crystals doped with Ge, Pb, Sb, or Sn. Carrier lifetimes longer than 40 ns together with long living SC field component makes the Ge, Sb, or Sn doped crystals as very promising photorefractive media for real time holographic devices.
Databáze: OpenAIRE
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