Nanopore-Patterned CuSe Drives the Realization of the PbSe-CuSe Lateral Heterostructure

When Machine Learning Meets 2D Materials: A Review

The availability of an ever-expanding portfolio of 2D materials with rich internal degrees of freedom (spin, excitonic, valley, sublattice, and layer pseudospin) together with the unique ability to tailor heterostructures made layer by layer in a precisely chosen stacking sequence and relative crystallographic alignments, offers an unprecedented platform for realizing materials by design. However, the breadth of multi-dimensional parameter space and massive data sets involved is emblematic of complex, resource-intensive experimentation, which not only challenges the current state of the art but also renders exhaustive sampling untenable. To this end, machine learning, a very powerful data-driven approach and subset of artificial intelligence, is a potential game-changer, enabling a cheaper - yet more efficient - alternative to traditional computational strategies. It is also a new paradigm for autonomous experimentation for accelerated discovery and machine-assisted design of functional 2D materials and heterostructures. Here, the study reviews the recent progress and challenges of such endeavors, and highlight various emerging opportunities in this frontier research area.

Realization of black phosphorus-like PbSe monolayer on Au(111) via epitaxial growth

Lead selenide (PbSe) has been attracted a lot attention in fundamental research and industrial applications due to its excellent infrared optical and thermoelectric properties, toward reaching the two-dimensional limit. Herein, we realize the black phosphorus-like PbSe (α-phase PbSe) monolayer on Au(111) via epitaxial growth, where a characteristic rectangular superlattice of 5 Å × 9 Å corresponding to 1 × 2 reconstruction with respect to the pristine ofα-phase PbSe is observed by scanning tunneling microscopy. Corresponding density functional theory calculation confirmed the reconstruction and revealed the driven mechanism, the coupling between monolayer PbSe and Au(111) substrate. The metallic feature of differential conductance spectra as well as the transition of the density of states from semiconductor to metal further verified such coupling. As the unique anisotropic structure, our study provides a pathway towards the synthesis of BP-PbSe monolayer. In addition, it builds up an ideal platform for studying fundamental physics and also excellent prospects in PbSe-based device applications.