Hopping conductivity and dielectric relaxation in Schottky barriers on GaN
| Autor: | I. A. Sheremet, M. V. Virko, P. N. Vorontsov-Velyaminov, Vladislav Voronenkov, Yu. G. Shreter, Ruslan Gorbunov, Natalia Bochkareva, V. S. Kogotkov, Andrey Leonidov |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Photoluminescence Condensed matter physics Band gap business.industry Schottky barrier Schottky diode 02 engineering and technology Dielectric Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Space charge Capacitance Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Condensed Matter::Materials Science 0103 physical sciences Relaxation (physics) Optoelectronics 0210 nano-technology business |
| Zdroj: | Semiconductors. 51:1186-1193 |
| ISSN: | 1090-6479 1063-7826 |
| DOI: | 10.1134/s1063782617090068 |
| Popis: | A study of the current and capacitance dependences on the forward voltage in Au/n-GaN Schottky diodes, the sub-band optical absorption spectra, and the defect photoluminescence in n-GaN bulk crystals and thin layers is reported. It is shown that defect-assisted tunneling is the dominant transport mechanism for forward-biased Schottky contacts on n-GaN. The dependences of the current and capacitance on forward bias reflect the energy spectrum of defects in the band gap of n-GaN: the rise in the density of deep states responsible for yellow photoluminescence in GaN with increasing energy and the steep exponential tail of states with an Urbach energy of E U = 50 meV near the conduction-band edge. A decrease in the frequency of electron hops near the Au/n-GaN interface results in a wide distribution of local dielectric relaxation times and in a dramatic transformation of the electric-field distribution in the space-charge region under forward biases. |
| Databáze: | OpenAIRE |
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