Carrier localization of as-grown {ital n}-type gallium nitride under large hydrostatic pressure

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.1322· OSTI ID:278529

Wetzel, C; Walukiewicz, W; Haller, E E; Ager, J III ^[1]; Grzegory, I; Porowski, S; Suski, T ^[2]

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1. Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States)
2. Unipress, Polish Academy of Sciences, 01-142 Warszawa (Poland)

A quantitative study of the carrier localization in GaN under large hydrostatic pressure is presented using infrared reflection and Raman spectroscopy. The free-carrier concentration in as-grown {ital n}-type GaN crystals is determined optically from the phonon-plasmon{endash}coupled mode and an analysis of the dielectric function. A strong decrease from 1{times}10{sup 19}cm{sup {minus}3} at ambient pressure to only 3{times}10{sup 17}cm{sup {minus}3} at a pressure of 27GPa is observed. This free-carrier reduction is attributed to a strongly localized donor present at a concentration of 1{times}10{sup 19}cm{sup {minus}3} and it is in agreement with previous qualitative results. From our quantitative data we determine the position of the neutral-donor level to be 126{sub {minus}5}{sup +20} meV below the conduction band at 27GPa. We present a model for the pressure dependence of the localized defect and predict its neutral level at 0.40{plus_minus}0.10eV above the conduction-band edge at ambient pressure. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Lawrence Berkeley National Laboratory
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 278529
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 3 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BAND THEORY
CARRIER MOBILITY
CRYSTAL DEFECTS
ELECTRIC CONDUCTIVITY
GALLIUM NITRIDES
HIGH PRESSURE
INFRARED SPECTRA
MEDIUM PRESSURE
N-TYPE CONDUCTORS
PRESSURE DEPENDENCE
RAMAN SPECTRA
SPECTRAL REFLECTANCE
VERY HIGH PRESSURE