Resonant tunneling in partially disordered silicon nanostructures

¹ Nanoscale Silicon Research Initiative, Department of Electrical and Computer Engineering, University of Rochester - Rochester NY 14627, USA
² Technische Universität of München, Physik-Department E16 D 85747 Garching, Germany
³ Institute for Microstructural Sciences, National Research Council Ottawa, Canada K1A 0R6
⁴ Institut d'Electronique et de Microélectronique du Nord Département Institut Supérieur d'Electronique du Nord 41 boulevard Vauban, 59046 Lille Cedex, France

Corresponding author: tsybeskov@ece.rochester.edu

Received: 8 January 2001
Accepted: 6 June 2001

Abstract

Low-temperature vertical carrier transport in layered structures comprised of nanocrystals separated in the growth direction by angstrom-thick layers exhibits entirely unexpected, well-defined resonances in conductivity. An unusual alternating current (ac) conductivity dependence on frequency and low magnetic field, negative differential conductivity, reproducible N-shaped switching and self-oscillations were observed consistently. The modeled conductivity mechanism is associated with resonant hole tunneling via quantized valence band states of nanocrystals. Tight-binding calculations of the quantum confinement effect for different nanocrystal sizes and shapes strongly support the tunneling model.