Carrier tunneling in nanocrystalline silicon–silicon dioxide superlattices: A weak coupling model

Differential conductivity measurements in partially disordered nanocrystalline Si--amorphous SiO₂ superlattices reveal a double-peak structure associated with tunneling via energy levels of light and heavy holes. The theoretical model and numerical simulations presented here show good agreement with experiment and predict that this system does not have stable solutions for an injected carrier concentration greater than 10¹⁷0.3em0excm^-3. Similar to a weakly coupled superlattice, a larger carrier concentration results in current instabilities. These instabilities have been observed and can be partially suppressed by using pulsed carrier photoinjection.