1. Growth and characterization of highly mismatched GaN1-xSbx alloys.
- Author
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Yu, K. M., Novikov, S. V., Min Ting, Sarney, W. L., Svensson, S. P., Shaw, M., Martin, R. W., Walukiewicz, W., and Foxon, C. T.
- Subjects
THIN film research ,GALLIUM nitride ,ANTIMONY ,LOW temperature physics ,ALLOYS - Abstract
A systematic investigation on the effects of growth temperature, Ga flux, and Sb flux on the incorporation of Sb, film structure, and optical properties of the GaN
1-x Sbx highly mismatched alloys (HMAs) was carried out. We found that the direct bandgap ranging from 3.4 eV to below 1.0 eV for the alloys grown at low temperature. At the growth temperature of 80 °C, GaN1-x Sbx with x > 6% losses crystallinity and becomes primarily amorphous with small crystallites of 2-5 nm. Despite the range of microstructures found for GaN1-x Sbx alloys with different composition, a well-developed absorption edge shifts from 3.4 eV (GaN) to close to 2 eV for samples with a small amount, less than 10% of Sb. Luminescence from dilute GaN1-x Sbx alloys grown at high temperature and the bandgap energy for alloys with higher Sb content are consistent with a localized substitutional Sb level ESb at ~1.1 eV above the valence band of GaN. The decrease in the bandgap of GaN1-x Sbx HMAs is consistent with the formation of a Sb-derived band due to the anticrossing interaction of the Sb states with the valence band of GaN. [ABSTRACT FROM AUTHOR]- Published
- 2014
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