Resonant tunnelling and fast switching in amorphous-carbon quantum-well structures

Abstract

The need for fast electronic devices working under extreme conditions, particularly at high temperature and high voltage, led researchers to investigate the use of films based ondiamond1-3, graphitic carbon4, amorphous carbon5 and other carbon nanostructures6.Inparallel, adifferent class of materials including disordered organic7, 8 and inorganic9-11 materials has been studied, particularly for fast switching and large-area inexpensive electronics based on quantum transport9, 12.However, fast-switching devices of amorphous semiconductors based on negative differential resistance or resonant tunnelling has not been achieved so far13, 14.Here, we show negative differential resistance peaks, quantized conductance and bias-induced switching with a high-frequency response from amorphous-carbon quantum-well structures. We also demonstrate sufficiently large values for the phase-coherence length and delocalized conduction in these band-modulated low-dimensional disordered carbon structures, which could lead to a new generation of unusual fast-switching devices. © 2006 Macmillan Publishers Limited. All rights reserved.