2021-05-17

Researchers adjust the substrate effect to affect the characteristics of atomic-level thickness semiconductors

By yqqlm yqqlm

Researchers adjust the substrate effect to affect the characteristics of atomic-level thickness semiconductors

However, in order to make further progress, scientists must strictly test This assumption is not only for a better understanding of single-layer physics, but also because the existence of the substrate effect brings the possibility of adjusting the characteristics of the layer by adjusting the substrate.

As reported in the Journal of Physical Review Letters, a team led by Taichang Jiang of the University of Illinois at Urbana-Champaign and his postdoctoral assistant Lin Mengkai used the Berkeley Lab’s Advanced Light Source (ALS) to detect two-dimensional Semiconductor-changes in the electronic properties of titanium telluride because of the increase in the thickness of platinum telluride. A single layer of titanium telluride is highly sensitive to the underlying substrate, which makes it particularly useful as a test case for studying substrate coupling effects.

The results show that as the thickness of the substrate increases, a dramatic systematic change occurs in the single-layer titanium telluride. An electronic phenomenon called charge density wave is suppressed, which is a characteristic of coupled charge and lattice distortion of a single layer of titanium telluride.

The combination of experimental results and first-principles theoretical simulations brings a detailed explanation of the fundamental quantum mechanical interaction between the single layer and the tunable substrate. The researchers concluded that the observed change is associated with the transition of the substrate from semiconductor to semi-metal as the thickness of the substrate increases.

This systematic study illustrates the key role played by the interaction of substrates in the physics of ultra-thin films. The new scientific understanding also provides a framework for the design and engineering of ultra-thin films to obtain Practical and enhanced material properties.