Hydrogenation of multiple‐quantum‐well optical‐modulator structures

We report studies of hydrogenated multiple‐quantum‐well (MQW) optical‐modulator structures via electron‐cyclotron‐resonance‐derived plasmas. Responsivity, optical transmission, current‐voltage, and capacitance‐voltage characterizations of Schottky‐ as well as pin‐diode modulator structures were performed. We find photocurrent‐collection efficiency and photoluminescence intensity to be enhanced by hydrogenation, with measurable improvement in electrically biased exciton‐absorption linewidth also seen. We interpret our results as arising from increased carrier lifetime in the MQW region, because of passivation of deep levels/defects. The improvements were stable after 550 °C heat treatment. These effects may be useful for improving the yield of usable MQW devices grown in a given system.