A mechanism of charge transport in Au-TiBx-n-GaN Schottky diodes with a space charge region considerably exceeding the De Broglie wavelength in GaN was studied. An analysis of the temperature dependences of the current-voltage characteristics of forward-biased Schottky barriers showed that, at 80 to 380K, the charge transport was performed by tunnelling along dislocations intersecting the space charge region. Estimation of the dislocation density, ρ, from the current-voltage characteristics, in accord with a model of tunnelling along the dislocation line, gave a value of ρ ≈ 1.7 x 107/cm2, which was close in magnitude to the dislocation density measured using X-ray diffractometry.

Mechanism of Dislocation-Governed Charge Transport in Schottky Diodes Based on Gallium Nitride. A.E.Belyaev, N.S.Boltovets, V.N.Ivanov, V.P.Kladko, R.V.Konakova, Y.Y.Kudrik, A.V.Kuchuk, V.V.Milenin, Y.N.Sveshnikov, V.N.Sheremet: Semiconductors, 2008, 42[6], 689-93