Stable continuous-wave lasing from discrete cesium lead bromide quantum dots embedded in a microcavity.

Area of Science:

• Materials Science
• Quantum Optics
• Nanotechnology

Background:

• All-inorganic cesium lead bromide (CsPbBr3) quantum dots (QDs) show high photoluminescence (PL) quantum efficiency, making them promising for laser gain materials.
• Isolated CsPbBr3 QDs have struggled to achieve lasing emission (LE) due to their limited absorption cross-section.

Purpose of the Study:

• To demonstrate continuous-wave lasing from isolated CsPbBr3 quantum dots.
• To overcome the limitations of finite absorption cross-section in single QDs for laser applications.
• To develop a stable, low-threshold microcavity laser platform using perovskite quantum dots.

Main Methods:

• Embedding isolated CsPbBr3 QDs within a polymer matrix.
• Constructing a vertical-cavity surface-emitting laser (VCSEL) using distributed Bragg reflectors (DBRs) and the QD-polymer composite.
• Characterizing the lasing emission properties, including threshold and Q factor.

Main Results:

• Achieved continuous-wave lasing from isolated CsPbBr3 QDs within a microcavity.
• Demonstrated stable single-mode lasing emissions with an ultra-low threshold of 8.8 W cm⁻².
• Obtained a high cavity quality factor (Q factor) of 1787.

Conclusions:

• Perovskite-based microcavity structures can sustain highly stable excitons at room temperature.
• This work provides a robust platform for studying single-particle nano-lasers.
• The developed system opens avenues for exploring quantum physics frontiers like exciton-polariton condensation and optical quantum communication.