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Title: Hopping conductivity and dielectric relaxation in Schottky barriers on GaN

Journal Article · · Semiconductors
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  1. Ioffe Institute (Russian Federation)
  2. Peter the Great St. Petersburg Polytechnic University (Russian Federation)
  3. St. Petersburg State University (Russian Federation)
  4. Financial University under the Government of the Russian Federation (Russian Federation)

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{sub 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.

OSTI ID:
22756381
Journal Information:
Semiconductors, Vol. 51, Issue 9; Other Information: Copyright (c) 2017 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7826
Country of Publication:
United States
Language:
English