Hopping conductivity and dielectric relaxation in Schottky barriers on GaN
- Authors: Bochkareva N.I.1, Voronenkov V.V.1, Gorbunov R.I.1, Virko M.V.2, Kogotkov V.S.2, Leonidov A.A.2, Vorontsov-Velyaminov P.N.3, Sheremet I.A.4, Shreter Y.G.1
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Affiliations:
- Ioffe Institute
- Peter the Great St. Petersburg Polytechnic University
- St. Petersburg State University
- Financial University under the Government of the Russian Federation
- Issue: Vol 51, No 9 (2017)
- Pages: 1186-1193
- Section: Physics of Semiconductor Devices
- URL: https://journals.rcsi.science/1063-7826/article/view/201162
- DOI: https://doi.org/10.1134/S1063782617090068
- ID: 201162
Cite item
Abstract
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 EU = 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.
About the authors
N. I. Bochkareva
Ioffe Institute
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
V. V. Voronenkov
Ioffe Institute
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
R. I. Gorbunov
Ioffe Institute
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
M. V. Virko
Peter the Great St. Petersburg Polytechnic University
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 195251
V. S. Kogotkov
Peter the Great St. Petersburg Polytechnic University
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 195251
A. A. Leonidov
Peter the Great St. Petersburg Polytechnic University
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 195251
P. N. Vorontsov-Velyaminov
St. Petersburg State University
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 199034
I. A. Sheremet
Financial University under the Government of the Russian Federation
Email: y.shreter@mail.ioffe.ru
Russian Federation, Moscow, 125993
Yu. G. Shreter
Ioffe Institute
Author for correspondence.
Email: y.shreter@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021