Hopping Conduction in Structures with Ge Nanoclusters Grown on Oxidized Si (001)

• Published in: Journal of nano research Vol. 39; pp. 178 - 188
• Main Authors: Kozyrev, Yurii N., Gomeniuk, Y.V., Kudina, Valeriya N., Garbar, Nikolay, Lysenko, Vladimir, Kondratenko, Sergey, Melnichuk, Yevgenij Ye
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.02.2016
• Subjects: Quantum Dots; Transport; Molecular Beam Epitaxy; Silicon-Germanium
• ISSN: 1662-5250; 1661-9897; 1661-9897
• DOI: 10.4028/www.scientific.net/JNanoR.39.178

Conductivity and capacitance in structures with Ge nanoclusters grown on oxidized Si (001) with different morphology have been investigated for the temperature range 120-290 K and frequencies 1 kHz-1MHz in co-planar geometry. It was found that structures exhibited T-1/3 conductivity dependence. The Mott’s variable range hopping through quasi-band of localized states at the Fermi level of Ge nanoclusters and their interfaces was found to be the dominant transport mechanism in the surface conductivity channel. The quasi-band width depends of surface morphology varying in the range 110-130 meV, while the middle of the band is located at Ev+140 meV. The peak of reduced conductivity and capacitance were observed under conditions when Fermi level is in the middle of this band.