BAND-STRUCTURE OF A SUPERLATTICE WITH A 2 WELL PERIOD

We present calculations for a superlattice with wells of alternating widths, w1 and w2, and barriers of alternating widths, b1 and b2, to investigate the effect of such a pattern in modulating superlattice minibands. Enormous changes in the electronic states of a superlattice can be made by adjusting width parameters in this way. The band structure of such a superlattice generally displays characteristics of both constituent superlattices, i.e. one with w1 and b1 and the other with w2 and b2. Whenever there is an overlap of minibands between the two constituent superlattices, a band splitting is observed in the composite structure. Enhancement of the minibands widths and the creation of new Bloch states can also be acheived by suitable arangements of the width parameters. These results are compared with recent calculations for a superlattice interleaved with a periodic array of δ-doped defects in the barrier or well layers. © 1992.