| Autor: |
Chauhan, P., Hasenöhrl, S., Dobročka, E., Chauvat, M. P., Minj, A., Gucmann, F., Vančo, Ľ., Kováč, J., Kret, S., Ruterana, P., Kuball, M., Šiffalovič, P., Kuzmík, J. |
| Předmět: |
|
| Zdroj: |
Journal of Applied Physics; 2019, Vol. 125 Issue 10, pN.PAG-N.PAG, 10p, 2 Color Photographs, 3 Black and White Photographs, 2 Diagrams, 5 Graphs |
| Abstrakt: |
Two I n x A l 1 − x N layers were grown simultaneously on different substrates [sapphire (0001) and the Ga-polar GaN template], but under the same reactor conditions, they were employed to investigate the mechanism of strain-driven compositional evolution. The resulting layers on different substrates exhibit different polarities and the layer grown on sapphire is N-polar. Moreover, for the two substrates, the difference in the degree of relaxation of the grown layers was almost 100%, leading to a large In-molar fraction difference of 0.32. Incorporation of In in I n x A l 1 − x N layers was found to be significantly influenced by the strain imposed by the under-layers. With the evolutionary process of In-incorporation during subsequent layer growth along [0001], the direction of growth was investigated in detail by Auger electron spectroscopy. It is discovered that the I n 0.60 A l 0.40 N layer grown directly on sapphire consists of two different regions with different molar fractions: the transition region and the uniform region. According to the detailed cross-sectional transmission electron microscopy, the transition region is formed near the hetero-interface due to the partial strain release caused by the generation of misfit-dislocations. The magnitude of residual strain in the uniform region decides the In-molar fraction. I n x A l 1 − x N layers were analyzed by structural and optical characterization techniques. Our present work also shows that a multi-characterization approach to study I n x A l 1 − x N is a prerequisite for their applications as a buffer layer. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
