Photoluminescence study of chloride VPE-grown GaN

Tetsuzo Ueda*, Masaaki Yuri, Heon Lee, James S. Harris, Takaaki Baba

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution


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.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsR.J. Shul, S.J. Pearton, F. Ren, C.S. Wu
PublisherMaterials Research Society
Number of pages6
Publication statusPublished - 1996
Externally publishedYes
EventProceedings of the 1996 MRS Spring Meeting - San Francisco, CA, USA
Duration: 1996 Apr 81996 Apr 12


OtherProceedings of the 1996 MRS Spring Meeting
CitySan Francisco, CA, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials


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