ELECTRONIC-STRUCTURE OF N-I-P-I SI SUPERLATTICES

The electronic structure of n-i-p-i Si superlattices is investigated b y the tight-binding renormalization method. Strong anistropy of the ho le masses in the in-plane direction is found and strong localization o f the electron and hole wave-functions in the growth direction is repo rted. For the structure studied, a type-II configuration is found with nearly zero overlap between electron and hole wave-functions. The lat ter property is discussed in view of its possible device applications.