Optical Studies of Laterally Confined Quantum Well Structures Grown on Ex-situ and In-situ Patterned Substrates.

摘要

This final technical report on ARO Contract No. DAAL03-89-K-0170 summarizes the issues examined and the findings related to (1) absorption and electroabsorption behavior of strained GaAs/InGaAs multiple quantum wells (MQW), (2) the dc transport characteristics of strained GaAs/InGaAs/AlAs based resonant tunnelling diodes, and (3) realization of three-dimensionally confined quantum well structures on patterned GaAs(111)B substrates via a one-step growth process labelled substrate encoded sized reducing epitaxy (SESRE). Use of pre-patterned substrates as a means of strain relief without the generation of dislocations is shown to allow growth of high quality MQWs to thicknesses of approx. 1 micron needed for sufficient optical interaction path length in p-i(MQW)-n modulators and detectors. The role of defect induced deep levels in impacting the exciton linewidth through their influence on the internal field distribution is revealed for the first time. Three dimensionally confined GaAs/AlGaAs structures are realized for the first time using SESRE....Strained quantum wells, Defect reduction, Patterned substrates, Electroabsorption, Modulators, Resonant tunnelling diodes, Lateral confinement, Quantum box, GaAs(100)/InGaAs,GaAs(111)B/AlGaAs.