The Effect of Ambient on Photoluminescence from GaN

The effect of ambient on photoluminescence (PL) from GaN was studied. We found that the PL intensity in vacuum was nearly four times higher than in air. The PL intensity also increased after etching the sample in Aqua Regia and BOE to remove the native oxide layer. After etching, the PL intensity was very stable in vacuum, but substantially degraded in air ambient. In HCl vapor (low pH), the PL intensity increased as compared to air ambient, while in NH3 vapor (high pH) it decreased. The quantum efficiency of the exciton and blue luminescence bands increased significantly with increasing excitation power density. This increase could not be explained by reduction of the depletion region width (field effect mechanism), but could be explained by changes in the nonradiative recombination rate at the surface (recombination mechanism). We therefore assume that in vacuum and acid vapor some surface species are desorbed or passivated, resulting in a decreased nonradiative recombination rate and increased PL intensity.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Physics and Applied Physics

Year dc:date.available

2011

Author dc:creator

• Ruchala, Iwona

Contributors dc:contributor

• Michael Reshchikov
• Alison Baski
• Umit Ozgur

• Ambient on PL in GaN
• Physical Sciences and Mathematics
• Physics

Statement dc:rights

• © The Author

Identifier

https://scholarscompass.vcu.edu/etd/226

OAI identifier oai:identifier

oai:scholarscompass.vcu.edu:etd-1225