Carrier transport in thin films of silicon nanoparticles

The electrical and electroluminescence characteristics of heterostructure systems containing thin films of visibly emitting silicon nanoparticles are shown to be controlled by carrier transport through the nanoparticulate films. A conduction mechanism encompassing both geometric and electronic effects most effectively relates the high resistivity with structural properties of the films. Heterostructure devices are constructed with silicon nanoparticle active layers produced by pulsed laser ablation supersonic expansion. The observed temperature-dependent photoluminescence, electroluminescence, and $I-V$ characteristics of the devices are consistent with a model in which carrier transport is controlled by space-charge-limited currents or tunneling through potential barriers on a percolating lattice.