Carrier localization of as-grown {ital n}-type gallium nitride under large hydrostatic pressure
- Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States)
- 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 Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 278529
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 53, Issue 3; Other Information: PBD: Jan 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Annealing studies of low-temperature-grown GaAs:Be
Carrier localization in gallium nitride