Document Type
Article
Original Publication Date
2009
Journal/Book/Conference Title
Applied Physics Letters
Volume
94
Issue
16
DOI of Original Publication
10.1063/1.3122934
Date of Submission
April 2015
Abstract
The effect of an ambient environment on the surface photovoltage and photoluminescence observed for GaN is studied. In air ambient the upward band bending gradually increases under UVillumination and is explained by the photoinduced chemisorption of surface adsorbates. Specifically, the increase in negative surface charge is consistent with the transfer of electrons from surface states or bulk to oxygen species physisorbed at the GaNsurface. In contrast, the upward band bending gradually decreases in vacuum under UVillumination and can be explained by the photoinduced desorption of these species. The photoadsorption and photodesorption of negatively charged species cause the surface depletion region to increase and decrease, respectively. This change in depletion region width is consistent with the observed decrease in photoluminescence intensity in air ambient and its significant increase in vacuum for a sample with low free electron concentration.
Rights
Foussekis, M., Baski, A.A., Reshcikov, M.A. Photoadsorption and photodesorption for GaN. Applied Physics Letters, 94, 162116 (2009). Copyright © 2009 AIP Publishing LLC.
Is Part Of
VCU Physics Publications
Comments
Originally published at http://dx.doi.org/10.1063/1.3122934