SAWTOOTH SUPERLATTICES IN A 2-BAND SEMICONDUCTOR

We consider electron dynamics in two-band semiconductor superlattices within the envelope function approximation. We develop a numerical method, based on the properties of the periodic continued fractions, to find the dispersion relation inside allowed minibands and to obtain the envelope functions. As an application, we concentrate on GaAs sawtooth-doped superlattices, consisting of periodic alternating n- and p-type delta-doped sheets separated by undoped material. Results are compared with one-band semiconductor predictions, and we find that coupling of bands in the host semiconductor indeed gives rise to relevant effects, especially for higher-minibands.