Low-threshold Colloidal Quantum Dots Polariton Lasing via a Strong Coupling Microcavity at Room Temperature

Abstract

Colloidal quantum dots (CQDs) are excellent optical gain media that can be synthesized through low-cost and easily controlled techniques, holding significant promise for applications in semiconductor laser devices. In this paper, we firstly demonstrated polariton coherent lasing based on a CdSe-based CQDs microcavity device at room-temperature (RT). The dispersion behaviors of CQDs polariton with different excitation power were analyzed comprehensively using angle-resolved spectroscopy techniques. The lasing behavior at threshold of 49μJ/cm2 and energy blue-shift are well fitting with the typical characteristics of robust polariton Bose-Einstein condensation (BEC) theory. Moreover, the linewidth of polariton lasing peak is narrowed down to 0.65 nm at 1.13Pth. Additionally, the polarization characteristics and temporal dynamics of the CQDs-microcavity polariton lasing are discussed. It is noted that the lifetime of CQDs polariton during condensation was reduced from 1.3 ns (0.8 Pth) to 68 ps (1.6 Pth). Our results provide valuable insights into the strong coupling low-threshold CQDs microcavity laser at RT, and promote its practical application in further.