Abstract
Acceptors responsible for the 2.2, 2.9 and 3.27 eV photoluminescence (PL) bands in undoped GaN were studied by transient PL. A non-exponential decay of PL intensity for all the three bands is observed at low temperature consistent with donor-acceptor pair recombination. The transitions are attributed to recombination involving a shallow donor and three different acceptors. At temperatures in excess of about 100 K a new recombination process emerges as evident from the nearly exponential PL decay. We attribute this to free-to-bound transitions involving free electrons and acceptors. Electron-capture cross-sections of 3 × 10-19, 2 × 10-20 and 3 × 10-21 cm2 are calculated for the acceptors responsible for the 3.27, 2.9 and 2.2 eV bands. These acceptors are attributed to multiply charged defects involving a gallium vacancy.
Original language | English (US) |
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Pages (from-to) | 1-7 |
Number of pages | 7 |
Journal | Physica B: Condensed Matter |
Volume | 325 |
DOIs | |
State | Published - Jan 2003 |
Funding
This work was supported by the National Science Foundation GOALI Program, under grant number DMR-970514.
Keywords
- Acceptors
- GaN
- Transient photoluminescence
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering