Researchers develop a novel technique for rising two-dimensional transition steel dichalcogenides – Uplaza

Nationwide College of Singapore (NUS) researchers have developed a novel phase-selective in-plane heteroepitaxial technique for rising two-dimensional transition steel dichalcogenides (2D TMDs). This strategy gives a promising technique for part engineering of 2D TMDs and fabricating 2D heterostructure units.

2D TMDs exhibit varied polymorphic constructions, together with 2H (trigonal prismatic), 1T (octahedral), 1T′ and T_d phases. These phases confer a variety of properties similar to superconductivity, ferroelectricity and ferromagnetism. By manipulating these structural phases, the wealthy bodily properties of TMDs might be tuned, enabling exact management over their traits by means of what is called part engineering.

On this work, a analysis crew led by Professor Andrew Wee from the Division of Physics below the NUS College of Science, in collaboration with worldwide companions, utilized molecular beam epitaxy (MBE) to develop molybdenum diselenide (MoSe₂) nanoribbons as an in-plane heteroepitaxial template to seed the expansion of H-phase chromium diselenide (CrSe₂).

MBE is a method for creating very skinny layers of supplies on a floor by depositing molecules one after the other. This enables for the exact management of the composition, thickness and construction of the deposited layers on the atomic degree.

Utilizing ultra-high vacuum scanning tunneling microscopy (STM) and non-contact atomic pressure microscopy (nc-AFM) strategies, the researchers noticed atomically sharp heterostructure interfaces with type-I band alignments and the attribute defects of mirror twin boundaries within the H-phase CrSe₂ monolayers. These mirror twin boundaries exhibited distinctive habits inside the confined one-dimensional digital system.

The analysis findings have been printed within the journal Nature Communications on 26 February 2024.

This analysis represents a continuation of the crew’s ongoing exploration into part construction management and bodily property research of 2D supplies.

Dr. Liu Meizhuang, the primary creator of the analysis paper, mentioned, “We have also realized the phase-selective growth of H-phase vanadium diselenide using this in-plane heteroepitaxial template. This phase-selective in-plane heteroepitaxial method has the potential to become a general and controllable way for expanding the library of 2D-TMD phase structures, thereby advancing fundamental research and device applications of specific 2D phases.”

Prof. Wee added, “The ability to control the phase of 2D lateral heterostructures opens many new opportunities in device applications.”