Quantum light emission from tunable GaAsxP1–x quantum-dots in wurtzite GaP nanowires

Quantum light emitters can be realized by employing semiconductor quantum-dots (QD) for advanced quantum optics and nanophotonic applications. Tunable Gallium Arsenide Phosphide (GaAsxP1–x) QD in nanowires (NWs) with emission in VIS-NIR wavelength range have a strong technological potential. Here, we synthesized crystal-pure wurtzite Gallium Phosphide (GaP) nanowires (NWs), incorporating single GaAsxP1–x QDs of various As content with a great degree of control over the shape and composition of the ternary alloy QD. A well-defined confinement of the QD and the tunability of the emission wavelength are confirmed by low-temperature micro-photoluminescence (μ-PL) spectroscopy showing that the QD NW emission is dominated by a narrow peak whose energy shifts according to the As content of the QD: from ∼650 nm (As = 70%) to ∼720 nm (As = 90%). Moreover, a localized and efficient carrier recombination mechanism is found by single-NW μ-PL mapping, confirming that this emission arises from the QD. Finally, a power and temperature dependent μ-PL study is performed to characterize the QD excitonic properties and to identify the origins and the nature of the involved energy levels.