Spontaneous off-stoichiometry as the knob to control the dielectric properties of gapped metals.

Autor: Khan MR; Centre of Excellence ENSEMBLE3 Sp. z o. o., Wolczynska Str. 133, 01-919, Warsaw, Poland. oleksandrmalyi@gmail.com., Gopidi HR; Centre of Excellence ENSEMBLE3 Sp. z o. o., Wolczynska Str. 133, 01-919, Warsaw, Poland. oleksandrmalyi@gmail.com., Darabian HR; Centre of Excellence ENSEMBLE3 Sp. z o. o., Wolczynska Str. 133, 01-919, Warsaw, Poland. oleksandrmalyi@gmail.com., Pawlak DA; Centre of Excellence ENSEMBLE3 Sp. z o. o., Wolczynska Str. 133, 01-919, Warsaw, Poland. oleksandrmalyi@gmail.com., Malyi OI; Centre of Excellence ENSEMBLE3 Sp. z o. o., Wolczynska Str. 133, 01-919, Warsaw, Poland. oleksandrmalyi@gmail.com.
Jazyk: angličtina
Zdroj: Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2023 Aug 02; Vol. 25 (30), pp. 20287-20294. Date of Electronic Publication: 2023 Aug 02.
DOI: 10.1039/d3cp01100c
Abstrakt: Using first-principles calculations and La 3 Te 4 as an example of an n-type gapped metal, we demonstrate that gapped metals can develop spontaneous defect formation resulting in off-stoichiometric compounds. Importantly, these compounds have different free carrier concentrations and can be realized by optimizing the synthesis conditions. The ability to tune the free carrier concentration allows the tailoring of the intraband and interband transitions, thus controlling the optoelectronic properties of materials in general. Specifically, by realizing different off-stoichiometric La 3- x Te 4 compounds, it is possible to reach specific crossings of the real part of the dielectric function with the zero line, reduce the plasma frequency contribution to the absorption spectra, or, more generally, induce metal-to-insulator transition. This is particularly important in the context of optoelectronic, plasmonic, and epsilon-near-zero materials, as it enables materials design with a target functionality. While this work is limited to the specific gapped metal, we demonstrate that the fundamental physics is transferable to other gapped metals and can be generally used to design a wide class of new optoelectronic/plasmonic materials.
Databáze: MEDLINE