Work

Investigation of nonequilibrium carrier transport in vanadium-doped CdTe and CdZnTe crystals using the time-resolved four-wave mixing technique

Year: 2003

Type: article

Abstract: We present a novel way to determine the type of dominant carrier photoexcited from deep traps in a photorefractive semiconductor. A numerical analysis of a picosecond free-carrier grating dynamics has revealed an excitation intensity dependent grating diffusive decay time τ D as well as effective carrier diffusion coefficient D , when the intensity varied in the range below that required to create a bipolar carrier plasma. According to the numerical analysis, an increase or decrease of effective diffusion coefficient D with excitation can be used as a criterion to distinguish the type of photogenerated carrier. We have verified this method experimentally by measuring dependences of effective D versus excitation density in a number of vanadium-doped and shallow-impurity codoped CdTe and ZnCdTe crystals, using for excitation a picosecond YAG:Nd laser ( h ν = 1.17 eV). The results were found to be in good agreement with predictions, based on carrier transport peculiarities in photorefractive crystals, and correlated well with the secondary ion mass spectroscopy data for each crystal.

Source: Semiconductor Science and Technology

DOI: 10.1088/0268-1242/18/4/330

Authors: M Sudzius, R Aleksiejunas, K Jarasiunas, D Verstraeten, J C Launay

Institutions: Vilnius University, Centre National de la Recherche Scientifique, Institut de Chimie de la Matière Condensée de Bordeaux

Language: English

Topic: Photorefractive and Nonlinear Optics

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funder: European Space Agency

Award: G7308083929