Vertical tubular zinc oxide microcavity enables efficient colloidal quantum dot lasing

Abstract

Colloidal quantum dots (CQDs) can potentially enable new classes of highly flexible, spectrally tunable lasers processible from solutions. Despite a considerable progress over the past years, colloidal-QD lasing is still an important challenge. We report vertical tubular zinc oxide (VT-ZnO) and lasing based on VT-ZnO/CsPb(Br0.5Cl0.5)3 CQDs composite. Due to regular hexagonal structure and smooth surface of VT-ZnO, the light emitted at around 525 nm is effectively modulated under 325 nm continuous excitation. The VT-ZnO/ CQDs composite finally shows lasing with a threshold of ∼ 46.9 µJ.cm-2 and a Q factor of ∼ 2978 under 400 nm femtosecond (fs) excitation. This ZnO based cavity can be complexed with CQDs easily, which may pave a new way of colloidal-QD lasing.