A novel light emitting device based on Si nanostructures and tunneling injection of carriers

Silicon was not used for light emitting devices (LEDs) as it is an indirect bandgap material and has very low radiative recombination rate and short photon lifetime. This fundamental material property limitation has been overcome. Recent efforts have demonstrated that the light emitting efficiency can be enhanced greatly and lasing effect is also possible with the low-dimensional (LD) silicon materials. In this work, a novel light- emitting device structure based on Si/SiO₂/LD Si/Si₃N₄/Si system is proposed. The low-dimensional Si governed the photon generation efficiency and energy spectrum whereas the asymmetry barrier heights formed by the SiO₂ and Si₃N₄ provide high efficiency carrier injection based on direct tunneling and maximizes the recombination events taking place in the LD Si region. Quantum calculations on the charge transports, including the direct tunneling carrier injection at the Si/SiO₂ interface and band-to-band recombination of in the LD Si, were conducted.