TY - JOUR

T1 - Optical and thermoelectric properties of non-Janus CuI and AgI, and Janus Cu2BrI and Ag2BrI monolayers by many-body perturbation theory

AU - Mohebpour, Mohammad Ali

AU - Mortazavi, Bohayra

AU - Zhuang, Xiaoying

AU - Tagani, Meysam Bagheri

N1 - Funding Information: B.M. and X.Z. appreciate the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453). B.M. is greatly thankful to the VEGAS cluster at the Bauhaus University of Weimar for providing the computational resources.

PY - 2022/9/7

Y1 - 2022/9/7

N2 - In an outstanding experimental advance in the field of two-dimensional nanomaterials, cuprous iodide (CuI) and silver iodide (AgI) monolayers have been grown via a novel graphene encapsulation synthesis approach [K. Mustonen, Adv. Mater. 34, 2106922 (2022)0935-964810.1002/adma.202106922]. Inspired by this accomplishment, we conduct first-principles calculations to investigate the elastic, phonon, and electron thermal transport, electronic, and optical properties of the non-Janus CuI and AgI and Janus Cu2BrI and Ag2BrI monolayers. Electronic and excitonic optical properties are elaborately studied using the many-body perturbation theory on the basis of GW approximation. Our results indicate that these novel systems are stable but with soft elastic modulus and ultralow lattice thermal conductivity. It is also shown that the studied monolayers are wide-gap semiconductors with exciton binding energies close to 1 eV. The spin-orbit induced band splitting of Janus monolayers are increased more than 100% under a uniaxial strain of 3%, and for non-Janus monolayers, a noticeable increase is observed under a perpendicular electric field. Thermoelectric efficiency of silver-based monolayers is higher than 1.2, making them promising candidates for next-generation thermoelectric devices. The presented first-principles results provide a deep understanding of the stability, thermal transport, and tunable optoelectronic properties of CuI, AgI, Cu2BrI, and Ag2BrI monolayers, which can serve as a guide for the oncoming studies.

AB - In an outstanding experimental advance in the field of two-dimensional nanomaterials, cuprous iodide (CuI) and silver iodide (AgI) monolayers have been grown via a novel graphene encapsulation synthesis approach [K. Mustonen, Adv. Mater. 34, 2106922 (2022)0935-964810.1002/adma.202106922]. Inspired by this accomplishment, we conduct first-principles calculations to investigate the elastic, phonon, and electron thermal transport, electronic, and optical properties of the non-Janus CuI and AgI and Janus Cu2BrI and Ag2BrI monolayers. Electronic and excitonic optical properties are elaborately studied using the many-body perturbation theory on the basis of GW approximation. Our results indicate that these novel systems are stable but with soft elastic modulus and ultralow lattice thermal conductivity. It is also shown that the studied monolayers are wide-gap semiconductors with exciton binding energies close to 1 eV. The spin-orbit induced band splitting of Janus monolayers are increased more than 100% under a uniaxial strain of 3%, and for non-Janus monolayers, a noticeable increase is observed under a perpendicular electric field. Thermoelectric efficiency of silver-based monolayers is higher than 1.2, making them promising candidates for next-generation thermoelectric devices. The presented first-principles results provide a deep understanding of the stability, thermal transport, and tunable optoelectronic properties of CuI, AgI, Cu2BrI, and Ag2BrI monolayers, which can serve as a guide for the oncoming studies.

UR - http://www.scopus.com/inward/record.url?scp=85138454332&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2204.10056

DO - 10.48550/arXiv.2204.10056

M3 - Article

AN - SCOPUS:85138454332

VL - 106

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 12

M1 - 125405

ER -