Effect of the aluminium concentration on the resonant tunnelling time and the laser wavelength of random trimer barrier Al_xGa_1−xAs superlattices

In this study, we investigated numerically the effect of aluminium concentration on the resonant tunnelling time (RTT) and the laser wavelength of random trimer barrier Al_xGa_1−xAs superlattices (RTBSL). Such systems consist of two different structures randomly distributed along the growth direction, with the additional constraint that the barriers of one kind appear in triply. An explicit formula is given for evaluating the transmission coefficient of superlattices (SL’s) with intentional correlated disorder. The method is based on Airy function formalism and the transfer-matrix technique. We discuss the impact of the aluminium concentration associated to the structural profile of the SL’s on the RTT and the laser wavelengths