Abstract
We have investigated photoluminescence (PL) and electron Hall mobility for unintentionally doped GaN epitaxial layers grown by low-pressure metalorganic chemical vapor deposition on c-plane Al2O3 substrates. Four GaN films having identical dislocation density but remarkably different electron Hall mobility were exploited. At low temperature (12K), a PL line associated with a bound exciton was observed and strong correlations were found between the Hall mobility and the PL intensity of the exciton transition. That is, relative PL intensity of the bound exciton to a donor-bound exciton monotonously increased with decreasing the electron mobility of the GaN films. This correlation was interpreted in terms of electrical compensation. Efforts to find the chemical origin of the PL line led to the conclusion that the BE line originated neither from threading dislocations nor from extrinsic point defects. Intrinsic acceptors such as Ga vacancy and GaN anti-site were suspected as plausible origin.
Original language | English |
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Pages (from-to) | 304-308 |
Number of pages | 5 |
Journal | Journal of Crystal Growth |
Volume | 260 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 2004 Jan 9 |
Externally published | Yes |
Keywords
- A1. Photoluminescence
- A3. Metalorganic chemical vapor deposition
- B1. GaN
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry