N. I. Bochkareva, V. V. Voronenkov, R. I. Gorbunov, M. V. Virko, V. S. Kogotkov, A. A. Leonidov, P. N. Vorontsov-Velyaminov, I. A. Sheremet, Yu. G. Shreter, “Hopping conductivity and dielectric relaxation in Schottky barriers on GaN”, Fizika i Tekhnika Poluprovodnikov, 2017, Volume 51, Issue 9,Pages <nobr>1235

This article is cited in 10 papers

Semiconductor physics

Hopping conductivity and dielectric relaxation in Schottky barriers on GaN

N. I. Bochkareva^a, V. V. Voronenkov^a, R. I. Gorbunov^a, M. V. Virko^b, V. S. Kogotkov^b, A. A. Leonidov^b, P. N. Vorontsov-Velyaminov^c, I. A. Sheremet^d, Yu. G. Shreter^a

^a Ioffe Institute, St. Petersburg
^b Peter the Great St. Petersburg Polytechnic University
^c Saint Petersburg State University
^d Finance Academy under the Government of the Russian Federation, Moscow

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 $E_{\operatorname{U}}$ = 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.

Received: 24.01.2017
Accepted: 09.02.2017

DOI: 10.21883/FTP.2017.09.44888.8528