Surface-Effect-Induced Optical Bandgap Shrinkage in GaN Nanotubes
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- 作者：Young S. Park ; Geunsik Lee ; Mark J. Holmes ; Christopher C. S. Chan ; Benjamin P. L. Reid ; Jack A. Alexander-Webber ; Robin J. Nicholas ; Robert A. Taylor ; Kwang S. Kim ; Sang W. Han ; Woochul Yang ; Y. Jo ; J. Kim ; Hyunsik Im
- 刊名：Nano Letters
- 出版年：2015
- 出版时间：July 8, 2015
- 年：2015
- 卷：15
- 期：7
- 页码：4472-4476
- 全文大小：346K
- ISSN：1530-6992
文摘
We investigate nontrivial surface effects on the optical properties of self-assembled crystalline GaN nanotubes grown on Si substrates. The excitonic emission is observed to redshift by 鈭?00 meV with respect to that of bulk GaN. We find that the conduction band edge is mainly dominated by surface atoms, and that a larger number of surface atoms for the tube is likely to increase the bandwidth, thus reducing the optical bandgap. The experimental findings can have important impacts in the understanding of the role of surfaces in nanostructured semiconductors with an enhanced surface/volume ratio.