TWINNING SUPERLATTICES

A new type of superlattice based on a periodic array of twinned stacki ng faults is proposed. Such superlattices based on Si and Ge are predi cted to be characterised by zero miniband energy gaps, evanescent stat e derived Bloch minibands and minibands with anomalous dispersion. The y can be direct band gap materials and offer the significant benefits of simple chemistry, lack of stress and a favoured technological envir onment.