Collective charge transport in semiconductor-metal hybrid nanocomposite

Abstract

Collective charge transport through a hybrid nanocomposite made of Ag nanoparticles (NPs) embedded in ultra-small Si quantum dot (QD) matrix exhibits unexpected and fascinating characteristics. Metallic inclusion (10 wt. % of Ag NPs) in the Si QD matrix affects six orders of magnitude increase in current. In the semiconductor-metal hybrid, three different charge transport mechanisms—quantum tunneling through insulating barriers, variable range hoping, and simple thermally activated conduction dominate in three different temperature regimes that are influenced by bias voltage. We show that there is a cross-over from one transport mechanism to the other and determine the voltage dependent cross-over temperatures.