Semiclassical and Quantum Transport in Si/SiO₂ Superlattices

Abstract

In the last few years, many research groups have been trying to develop electroluminescent devices based on silicon. In particular, it has been shown that low-dimensional structures, such as silicon clusters, quantum wires and quantum wells, are suitable for this purpose. In this work we investigate transport properties of a particular superlattice using two approaches. The first method is a Monte Carlo simulation of electron transport in the biased superlattice. The band structure is calculated using the envelope function approximation, and the scattering mechanisms introduced in the simulator are confined optical phonons. Owing to the particularly flat band structure, drift velocities are very low, but it will be shown that a parallel component of the electric field can significantly increase the vertical drift velocity. Moreover, a superlattice based device is proposed in order to obtain high recombination efficiency. Finally, a quantum calculation is introduced, in order to describe with higher accuracy the high field transport regime.