抄録
We have examined the effect of growth conditions on photoluminescence (PL) characteristics of chloride VPE-grown GaN films. Undoped GaN films are grown on sapphire by a newly developed chloride VPE system which utilizes GaCl 3 and NH 3 as source materials. We find that the spectra depend strongly on the growth temperatures and the corresponding surface morphology. Peaks from excitons and donor-acceptor pairs (D-A pair) recombination are observed for the films with terrace-like flat surfaces grown at between 950°C and 1000°C. A peak due to exciton bound to neutral donors is observed for a growth temperature of 975°C where the acceptor-related peaks are not seen. Decreasing the growth temperature below 950°C causes rough surfaces due to three-dimensional growth, whereas increasing the growth temperature above 1000°C causes cracks or partial pealing off of the film. The films with rough surfaces or crystal failures show broad emission from deep acceptor levels. As a result, residual acceptors are eliminated in the very narrow range of the growth temperature around 975°C. It is also noted that an increase of the V/III ratio during the growth makes the line width of the band-edge peak narrower. The PL results show that a growth temperature around 975°C and high V/III ratio are essential to obtain better crystal quality and reduced concentration of residual acceptors.
本文言語 | English |
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ホスト出版物のタイトル | Materials Research Society Symposium - Proceedings |
編集者 | R.J. Shul, S.J. Pearton, F. Ren, C.S. Wu |
出版社 | Materials Research Society |
ページ | 189-194 |
ページ数 | 6 |
巻 | 421 |
出版ステータス | Published - 1996 |
外部発表 | はい |
イベント | Proceedings of the 1996 MRS Spring Meeting - San Francisco, CA, USA 継続期間: 1996 4月 8 → 1996 4月 12 |
Other
Other | Proceedings of the 1996 MRS Spring Meeting |
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City | San Francisco, CA, USA |
Period | 96/4/8 → 96/4/12 |
ASJC Scopus subject areas
- 電子材料、光学材料、および磁性材料