Boost Lasing Performances of 2D Semiconductor in a Hybrid Tungsten Diselenide Monolayer/Cadmium Selenide Quantum Dots Microcavity Laser

Abstract

Monolayer (ML) transition metal dichalcogenides (TMDCs) are suitable for use in low-threshold, room-temperature lasers. 2D semiconductor lasers are coherent, compact, and are suitable for multispectral light sources. 0D quantum dot technology has been applied in broadband-emitting devices and high-quality display systems. Herein, dual-color continuous-wave microcavity lasers are investigated by integrating a tungsten diselenide (WSe2) monolayer and cadmium selenide (CdSe) quantum dots (QDs) into a single microdisk cavity. The hybrid TMDC/QD microcavity device not only achieves lasing in two distinct wavelength regions but also boosts the lasing performances of the WSe2 monolayer due to the energy conversion between the two gain materials. Variations in the spectra obtained under power-dependent lasing are examined, and the temporal coherence properties of the lasing signals are also characterized to verify the lasing actions. The results indicate that the lasing threshold of the 2D WSe2 monolayer cavity with the CdSe QDs is reduced by more than 2.5 times compared with the WSe2 cavity without the QDs. These findings both expand the wavelength range of TMDC-based compact lasers at room temperature and facilitate their implementation in applications such as photonic integrated circuits, broadband light-emitting diodes, and quantum display systems.