Optical and electrical properties of Te doped AlGaAsSb/AlAsSb Bragg mirrors on InP

Abstract

We present a comparative study carried out on the optical and electrical characteristics of undoped and Te doped AlGaAsSb/AlAsSb Bragg mirrors with 6.5 pairs of layers and bulk undoped and Te doped AlGaAsSb epilayers alloys lattice matched on InP, grown by molecular beam epitaxy, using SIMS, photoluminescence, reflectivity and IxV techniques. The temperature dependence of PL transitions observed in the Bragg mirrors are similar to that observed in bulk samples and associated with the donor and acceptor recombinations in alloys with electrostatic potential fluctuations described by quasi-donor-acceptor-pair (QDAP) models. We verifi ed by SIMS the presence of a macro fluctuation in the Te profi le concentrations in the growth direction of the doped Bragg mirror. The influence of doping, alloy and macrofluctuation of incorporated Te on the optical and electrical properties of doped Bragg mirror is analyzed. The AlGaAs/AlAsSb seems a very attractive option for VCSEL technology.

A infuência de diferentes interfaces nas características elétricas e ópticas de Espelhos de Bragg de ALGaAsSB/ALAsSB dopados com Te, sobre InP.

“…The employment of δ-doping and digital alloy gradient interface structures reduces the voltage threshold value a little and improves the electrical conduction in mirrors. Another factor that may influence the voltage threshold is the asymmetry found in the doping concentration along the quaternary layer, as observed by Toginho Filho et al (2006). The serial resistance of the mirror doped with digital alloy presents a reduction of over than 50% in comparison with value observed for samples with homogeneous doping.…”