CHARACTERIZATION OF HYDROGENATED GAAS ALGAAS MULTIPLE-QUANTUM-WELL STRUCTURES/

We report on the photoluminescence properties and the hydrogen depth d istributions of plasma treated GaAs/AlGaAs multiple quantum well (MQW) structures. Specimens grown by molecular beam epitaxy were exposed to a deuterium plasma under different temperature-time conditions. Photo luminescence measurements were made at 4.2 K, using low and high excit ation powers, on the hydrogenated samples and on untreated partners. A decrease in the linewidth of the free exciton and an increase in the peak intensity were observed in specimens following plasma treatment. In general, each of the hydrogenated MQW specimens displayed an increa se in luminescence efficiency and a diminution of impurity-related pea ks after hydrogenation. Secondary ion mass spectrometry measurements y ielded depth distributions for H-2 and Al atoms. In samples having the best luminescence, the H-2 was nearly constant throughout the MQW reg ion, at about 10(18) cm-3.