Photoelectric effects in MQW structures of diamond-like carbon films

Abstract

Multilayered quantum-dimensional structures were investigated containing 1 to 10 potential wells produced by alternating diamond-like carbon films with two values of the forbidden gap width (mobility gap) on silicon substrates. Current-voltage, charge-voltage and charge transient characteristics for different temperatures and illumination intensities as well as photoresponse kinetics were studied. Areas of a negative differential conductance were revealed at both low and room temperatures, which may be considered as a manifestation of a resonant tunnelling injection of minority carriers with the pulse normal to the quantum-dimensional layers of the diamond-like carbon films. This phenomenon becomes significantly more pronounced when the multiple quantum well (MQW) structures are illuminated, being strongest in the samples having the thickness of the two outer barrier carbon films of the MQW structure two times lower than that of the internal barrier films. The investigation results confirm a possibility of manufacturing and using MQW structures based on diamond-like carbon films in micro- and nanoelectronics, particularly as resonant tunnelling devices (diodes, transistors, etc.).