Room temperature observation of optical modes in transferred rolled-up InGaAs/GaAs quantum dot microtube with AlGaAs confining layers

摘要

We realized the excellent confinement of carriers in single- layer InAs quantum dots (QDs) via introducing two AlGaAs confining layers (CLs), and then fabricated the corresponding rolled-up InGaAs/GaAs QD microtubes by conventional photolithography and wet-etching. Subsequently, the as-fabricated AlGaAs confined QD microtubes were transferred to a Si-based SiOx substrate using a simple liquid-assisted substrate-on-substrate transfer process, thus obtaining the microtube ring resonators. Through micro-photoluminescence (mu PL) measurement, optical modes were observed at room temperature and a maximum Q-factor of similar to 550 was demonstrated. In order to clearly show the effect of AlGaAs CLs, we also fabricated and transferred QD microtubes without AlGaAs CLs for comparison. mu PL spectra collected at 80 K confirmed that the PL intensity of the central optical mode was increased similar to 10 times with the assistance of AlGaAs CLs. We have confidence that QD microtube ring resonators can be further improved through the incorporation of double-layer QDs together with AlGaAs CLs.