Perovskite Quantum Dot Lasing in a Gap-Plasmon Nanocavity with Ultralow Threshold.

Hsieh, Yu-Hung; Hsu, Bo-Wei; Peng, Kang-Ning; Lee, Kuan-Wei; Chu, Chih Wei; Chang, Shu-Wei; Lin, Hao-Wu; Yen, Ta-Jen et al. · ACS Nano · 2020

basic_science · Level V

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Abstract

Lead halide perovskite materials have recently received considerable attention for achieving an economic and tunable laser owing to their solution-processable feature and promising optical properties. However, most reported perovskite-based lasers operate with a large lasing-mode volume, resulting in a high lasing threshold due to the inefficient coupling between the optical gain medium and cavity. Here, we demonstrate a continuous-wave nanolasing from a single lead halide perovskite (CsPbBr<sub>3</sub>) quantum dot (PQD) in a plasmonic gap-mode nanocavity with an ultralow threshold of 1.9 Wcm<sup>-2</sup> under 120 K. The calculated ultrasmall mode volume (∼0.002 λ<sup>3</sup>) with a <i>z</i>-polarized dipole and the significantly large Purcell enhancement at the corner of the nanocavity inside the gap dramatically enhance the light-matter interaction in the nanocavity, thus facilitating lasing. The demonstration of PQD nanolasing with an ultralow-threshold provides an approach for realizing on-chip electrically driven lasing and integration into on-chip plasmonic circuitry for ultrafast optical communication and quantum information processing.