Spin polarization of carriers in resonant tunneling devices containing InAs self-assembled quantum dots. (December 2015)

• Record Type: Journal Article
• Authors: Nobrega, J. Araújo e; Gordo, V. Orsi; Galeti, H.V.A.; Gobato, Y. Galvão; Brasil, M.J.S.P.; Taylor, D.; Orlita, M.; Henini, M.
• Is Part Of: Superlattices and microstructures. Volume 88(2015)
• Page Start: 574
• Page End: 581
• Publication Date: 2015-12
• Subjects: Resonant tunneling diodes -- Photoluminescence -- Magneto-photoluminescence -- Spintronics -- Spin polarization -- Quantum dots; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2015.10.018
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: In this work, we have investigated transport and optical properties of n-i-n resonant tunneling diodes (RTDs) containing a layer of InAs self-assembled quantum dots (QDs) grown on a (311)B oriented GaAs substrate. Polarization-resolved photoluminescence (PL) and magneto-transport measurements were performed under applied voltage and magnetic fields up to 15 T at 2 K under linearly polarized laser excitation. It was observed that the QD circular polarization degree depends strongly on the applied voltage. Its voltage dependence is explained by the formation of excitonic complexes such as positively (X + ) and negatively (X − ) charged excitons in the QDs. Our results demonstrate an effective electrical control of an ensemble of InAs QD properties by tuning the applied voltage across a RTD device into the resonant tunneling condition. Highlights: The charge state and spin polarization of InAs quantum dots in resonant tunneling diodes can be voltage controlled. The voltage control of spin polarization degree was associated to the formation of different excitonic complexes in the QDs. The spin polarization degree presents a maximum value (∼−37% at 15T) around the hole resonant tunneling condition.