Chemically stable quantum-confined 2D metals are of interest in next-generation nanoscale quantum devices. Bottom-up design and synthesis of such metals could enable the creation of materials with tailored, on-demand, electronic and optical properties for applications that utilize tunable plasmonic coupling, optical non-linearity, epsilon-near-zero behavior, or wavelength-specific light trapping. In this work, we demonstrate that the electronic, superconducting and optical properties of air-stable two-dimensional metals can be controllably tuned by the formation of alloys. Environmentally robust large-area two-dimensional InxGa1-x alloys are synthesized by Confinement Heteroepitaxy (CHet). Near-complete solid solubility is achieved with no evidence of phase segregation, and the composition is tunable over the full range of x by changing the relative elemental composition of the precursor. The optical and electronic properties directly correlate with alloy composition, wherein the dielectric function, band structure, superconductivity, and charge transfer from the metal to graphene are all controlled by the indium/gallium ratio in the 2D metal layer.
@article{arxiv.2106.00117,
title = {Tunable Two-Dimensional Group-III Metal Alloys},
author = {Siavash Rajabpour and Alexander Vera and Wen He and Benjamin N. Katz and Roland J. Koch and Margaux Lassaunière and Xuegang Chen and Cequn Li and Katharina Nisi and Hesham El-Sherif and Maxwell T. Wetherington and Chengye Dong and Aaron Bostwick and Chris Jozwiak and Adri C. T. van Duin and Nabil Bassim and Jun Zhu and Gwo-Ching Wang and Ursula Wurstbauer and Eli Rotenberg and Vincent Crespi and Su Ying Quek and Joshua A. Robinson},
journal= {arXiv preprint arXiv:2106.00117},
year = {2021}
}