Relaxation of stored charge carriers in a Zn sub 0. 3 Cd sub 0. 7 Se mixed crystal

Journal Article · Thu Mar 15 00:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.5178· OSTI ID:6860776

Lin, J Y; Jiang, H X ^[1]

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1. Department of Physics, Kansas State University, Cardwell Hall, Manhattan, Kansas 66506-2601 (USA)

Persistent photoconductivity (PPC) has been investigated in detail in a Zn{sub 0.3}Cd{sub 0.7}Se mixed crystal. Two different temperature conductivity states have been observed. Relaxation of stored charge carriers, which contribute to PPC, has been studied at different conditions. We find that the decay of PPC follows the stretched-exponential'' function that is usually observed in a wide class of disordered materials. At {ital T}{lt}220 K, the relaxation time increases with increase of temperature. At a constant temperature, the relaxation time increases with increase of excitation photon dose, which is a consequence of the presence of the two different conductivity states. However, at a constant temperature, the decay exponent is excitation-photon-dose independent, while the characteristic decay time constant depends on excitation photon dose. The PPC observed here thus exhibits characteristic phenomena of disordered systems, which suggests that the random local-potential fluctuations, which arise from the compositional fluctuations, are responsible for PPC. PPC-decay behavior is also analyzed for some of the previously published data on other materials. We find that the stretched-exponential function describes the PPC decay in various materials at low temperatures.

• OSTI ID: 6860776
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 41:8; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CADMIUM SELENIDES
CHARGE CARRIERS
PHOTOCONDUCTIVITY
ZINC SELENIDES
FLUCTUATIONS
ORDER-DISORDER TRANSFORMATIONS
RELAXATION TIME
TEMPERATURE DEPENDENCE
CADMIUM COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SELENIDES
SELENIUM COMPOUNDS
VARIATIONS
ZINC COMPOUNDS
360603* - Materials- Properties