Quantum dots derived from two-dimensional transition metal dichalcogenides: synthesis, optical properties and optoelectronic applications.

Zero-dimensional transition-metal-dichalcogenides (TMD) quantum dots (QDs) have attracted a lot of attention due to their interesting fundamental properties and various applications. Compared to TMD monolayers, the QD counterpart exhibits larger direct transition energies, exciton binding energies, absorption coefficient, luminescence efficiency, and specific surface area. These characteristics make them useful in optoelectronic device applications. In this review, recent exciting progress on TMD-QD based synthesis, optical properties, and applications are highlighted. The first part of this article begins with a brief description of the synthesis approaches, which focus on the microwave-assistant heating and pulsed laser ablation methods. The second part introduces the fundamental optical properties of TMD QDs such as quantum confinement in optical absorption, excitation-wavelength-dependent photoluminescence, and many-body effects. These properties are highlighted. In the third part, the new developments on TMD-QD-based optoelectronic devices, including light-emitting diodes, solar cells, photodetectors, optical sensors, and light-controlled memory devices are addressed. Finally, a brief summary and outlook are given.&#xD.