AlGaAs/GaAs multiple quantum well reflection modulators grown on Si substrates

Abstract

We report for the first time large excitonic absorption at room temperature in AlGaAs/GaAs multiple quantum well structures grown on Si substrates in a p-i-n configuration, using photocurrent measurements. We demonstrate an optical reflection modulator which is based on the quantum-confined Stark effect and exciton broadening with a reverse bias voltage applied across the p-i-n structure. A 7.7% change in the reflectivity of the device with 6 V reverse bias voltage was observed. These results demonstrate clearly that optical device quality AlGaAs/GaAs is obtainable directly on Si substrates which has great implications with regard to the monolithic integration of optical III-V and electronic Si technology.