OBSERVATION OF 1.5 MU-M QUANTUM-CONFINED STARK-EFFECT IN INGAAS ALGAAS MULTIPLE-QUANTUM WELLS ON GAAS SUBSTRATES/

We demonstrate the quantum confined Stark effect near 1.5 mu m in the LnGaAs/AlGaAs quantum wells grown on GaAs. This is achieved through th e successful growth of very highly mismatched InGaAs/AlGaAs multiple q uantum wells (MQWs) on GaAs substrates by molecular beam epitaxy. In t hese devices, linearly graded InGaAs buffer layers are grown beneath t he MQWs to minimize threading dislocations. Furthermore, to improve th e material quality and interface smoothness of the MQWs, a very low gr owth temperature (280 degrees C) is used in addition to a one monolaye r deposition of GaAs and growth interruptions on both sides of quantum wells. These devices clearly exhibit the quantum confined Stark effec t as measured by electroabsorption at 300 K. (C) 1995 American Vacuum Society.