Collective charge transport in semiconductor-metal hybrid nanocomposite

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. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790300]