Nanolasers, with small footprint and ultralow threshold, are promising for applications in data communication, on-chip optical computing, and optical interconnects. In addition to the microcavity design, the choice of gain material is another critical factor determining the optical performance of nanolasers. 2D materials are widely studied and applied in nanoscale optoelectronic devices due to their exceptional electrical, chemical, thermal, and optical properties caused by the unique layered structures. As emerging materials with unique optical properties, 2D materials are selected as effective gain materials for designing of nanolasers. In this review, the recent advances in nanolasers based on 2D materials are comprehensively addressed.

An ultrathin near-perfect MoSe 2 absorber working in the visible regime is demonstrated theoretically and experimentally, and it consists of a MoSe 2 /Au bi-layer film. The polymerassisted deposition method is used to synthesize MoSe 2 films, which can reduce the roughness and thus improve the film absorption. Simulation results show that the absorption of the absorber with 22 nm MoSe 2 reaches to larger than 90% between 628.5 nm and 718 nm with a peak value up to 99.5% at 686 nm. Moreover, the measured absorption also shows near-perfect absorption of this simple absorber. Finally, an ultrathin photodetector is fabricated based on this perfect absorber and shows on/off reproducibility and remarkable photocurrent, which is three orders of magnitude higher than the dark current.

This review summarizes the recent progress made in using cobalt-based catalysts for photo/electrocatalytic CO2 reduction.

Monolayer transition metal dichalcogenides (TMDs) show promising potential for next-generation optoelectronics due to excellent light capturing and photodetection capabilities. Photodetectors, as important components of sensing, imaging and communication systems, are able to perceive and convert optical signals to electrical signals. Herein, the large-area and high-quality lateral monolayer MoS2/WS2 heterojunctions were synthesized via the one-step liquid-phase chemical vapor deposition approach. Systematic characterization measurements have verified good uniformity and sharp interfaces of the channel materials. As a result, the photodetectors enhanced by the photogating effect can deliver competitive performance, including responsivity of ~ 567.6 A/W and detectivity of ~ 7.17 × 1011 Jones. In addition, the 1/f noise obtained from the current power spectrum is not conductive to the development of photodetectors, which is considered as originating from charge carrier trapping/detrapping. Therefore, this work may contribute to efficient optoelectronic devices based on lateral monolayer TMD heterostructures.

No abstract