Inlaid ReS₂ Quantum Dots in Monolayer MoS₂

Abstract

Two-dimensional (2D) transition-metal dichalcogenides\n(TMDs) are\nprospective materials for quantum devices owing to their inherent\n2D confinements. They also provide a platform to realize even lower-dimensional\nin-plane electron confinement, for example, 0D quantum dots, for exotic\nphysical properties. However, fabrication of such laterally confined\nmonolayer (1L) nanostructure in 1L crystals remains challenging. Here\nwe report the realization of 1L ReS₂ quantum dots epitaxially\ninlaid in 1L MoS₂ by a two-step chemical vapor deposition\nmethod combining with plasma treatment. The lateral lattice mismatch\nbetween ReS₂ and MoS₂ leads to size-dependent\ncrystal structure evolution and in-plane straining of the 1L ReS₂ quantum dots. Optical spectroscopies reveal the abnormal\ncharge transfer between the 1L ReS₂ quantum dots and the\nMoS₂ matrix, resulting from electron trapping in the 1L\nReS₂ quantum dots. This study may shed light on the development\nof in-plane quantum-confined devices in 2D materials for potential\napplications in quantum information.