Photo-induced Wavelength-tuning of Telecom-band Quantum Dot Nanowires Embedded in a Phase Change Material

Abstract: Scalable quantum-photonic technologies require spatially separated emitters to emit at the same wavelength, yet epitaxially grown quantum dots naturally exhibit emitter-to-emitter variations in their emission energies. Here, we demonstrate a contact-free post-growth tuning approach for InAs quantum dots embedded in InP nanowires using the photo-induced transformation of an amorphous Sb2S3 shell. This photoinduced effect leads to a progressive relaxation of the strain imposed on the InP core, enabling controlled spectral tuning of the quantum-dot emission. The effect is observed both at room temperature and under cryogenic conditions for quantum dots emitting in the O-band of the telecommunications spectrum. Strain-induced redshifts of approximately 7 meV at room temperature and 28 meV under cryogenic conditions are observed, respectively. The use of an amorphous chalcogenide shell therefore provides a route to achieve local wavelength tuning at the single quantum-dot-in-a-nanowire level after growth. This approach could enable spectrally matched emitters for scalable quantum-photonic architectures.