Hydrogenation of GaSb/GaAs quantum rings

Hodgson, Peter and Hayne, Manus and Ahmad Kamarudin, Mazliana and Zhuang, Qiandong and Birindelli, Simone and Capizzi, Mario (2014) Hydrogenation of GaSb/GaAs quantum rings. Applied Physics Letters, 105: 081907. ISSN 0003-6951

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Abstract

We present the results of photoluminescence measurements on hydrogenated type-II GaSb/GaAs quantum dot/ring (QD/QR) samples at temperatures ranging from 4.2K to 400 K. Hydrogenation is found to suppress optically induced charge depletion (associated with the presence of carbon acceptors in this system). A redshift of the QD\QR emission energy of a few tens of meV is observed at temperatures 300 K, consistent with a reduction in average occupancy by 1 hole. These effects are accompanied by a reduction in PL intensity post-hydrogenation. We conclude that although hydrogenation may have neutralized the carbon acceptors, multiple hole occupancy of type-II GaSb/GaAs QD/QRs is very likely a precondition for intense emission, which would make extending the wavelength significantly beyond 1300 nm at room temperature difficult.