ELECTRONIC STATES IN GAAS AL0.3GA0.7AS NONPERIODIC SUPERLATTICES/

Transmission and photoluminescence measurements in GaAs/Al0.3As0.7As s uperlattices in which the layer widths vary randomly, illustrate the e ffects of one-dimensional non-periodic potentials on electronic energy states. The fundamental interband transition energy in the non-period ic structures is lower than that in the periodic case. A relation betw een this shift and the wavefunction localization length is derived. Th e PL emission from the non-periodic samples is ten to twenty times str onger than from the periodic samples.