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HL: Fachverband Halbleiterphysik

HL 33: Optical properties

HL 33.6: Vortrag

Dienstag, 17. März 2020, 15:15–15:30, POT 112

Spectroscopic investigation of the radiative efficiency of ordered GaAs/(In,Ga)As core/shell nanowire arrays — •Michał Góra, Miriam Oliva, Jesús Herranz, Manfred Ramsteiner, Lutz Geelhaar, and Oliver Brandt — Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117 Berlin, Germany

The vapor-liquid solid growth of GaAs nanowires on Si enables the integration of the III-As semiconductors on a Si platform for optoelectronic applications. In addition, GaAs/(In,Ga)As core/shell nanowires allow us to extend the emission wavelength toward the telecommunication range. An important question for actual applications of these structures is their internal quantum efficiency for longer emission wavelengths. In the present study, we utilize temperature- and power-dependent photoluminescence spectroscopy to investigate the radiative efficiency of ordered GaAs/(In,Ga)As core/shell nanowire arrays synthesized by molecular beam epitaxy. The shell consists of either (In,Ga)As quantum wells with different In content or an InAs/(In,Ga)As dot-in-a-well structure. The absolute efficiency is determined by comparison with GaAs/(Al,Ga)As core/shell nanowires with known internal quantum efficiency. Our results show that the internal quantum efficiency of the (In,Ga)As quantum well shell decreases strongly with increasing In content. However, InAs/(In,Ga)As dot-in-a-well shells are found to enable emission wavelengths in the telecommunication O band at 1.26 µm, while maintaining a comparatively high quantum efficiency up to room temperature.