Deep levels and persistent photoconductivity in GaN thin films

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.118799· OSTI ID:534435

Qiu, C H; Pankove, J I ^[1]

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1. Astralux Incorporated, Boulder, Colorado 80301 (United States)

Photocurrent decay in GaN thin films was studied in the time span from a few seconds to several days. The persistent photoconductivity (PPC) behavior was observed not only in Mg-doped {ital p}-type GaN films but also in undoped {ital n}-type GaN films. The photoconductivity spectra and the photocurrent response time were measured using a weak probe light at several times after the samples had been kept in the dark. During the relaxation, the photocurrent due to the subband-gap probe light decreased more than the photocurrent due to the UV probe light. It is suggested that metastable centers at 1.1, 1.40, and 2.04 eV above the valence band edge are responsible for the PPC behavior in Mg-doped GaN, and that Ga vacancy is the candidate for PPC effect in {ital n}-type GaN. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 534435
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 15 Vol. 70; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DOPED MATERIALS
ENERGY LEVELS
GALLIUM NITRIDES
MAGNESIUM ADDITIONS
PHOTOCONDUCTIVITY
THIN FILMS
ULTRAVIOLET RADIATION