Quasiparticle bands and optical properties of SnSe from an ab initio approach

Author(s)

Melendez, Juan J. ^{[1, 2]} ; Gonzalez-Romero, Robert L. ^[3] ; Antonelli, Alex ^[4]

Affiliation

^[1] Univ Extremadura, Dept Phys, Ave Elvas S-N, Badajoz 06006 - Spain

^[2] Inst Adv Sci Comp Extremadura ICCAEx, Ave Elvas S-N, Badajoz 06006 - Spain

^[3] Univ Pablo Olavide, Dept Sistemas Fis Quim & Nat, Ctra Utrera, Km 1, Seville 41013 - Spain

^[4] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Sao Paulo - Brazil

• Document type: Journal article
• Source: COMPUTATIONAL MATERIALS SCIENCE; v. 152, p. 107-112, SEP 2018.
• Web of Science Citations: 1

Abstract

We present an ab initio study of the nature of the optical and quasiparticle gaps of SnSe. The density functional theory and the many-body perturbation theory under the GW approximation show that SnSe exhibits an indirect quasiparticle bandgap of 0.64 eV, which agrees with the experimental evidence. The optical gap, on the contrary, is direct and ranges between 0.9 and 1.1 eV for thin films. The optical absorption spectrum of SnSe evidences the formation of excitons, whose binding energies depend on the polarization of the incident electric field. Finally, we show evidences that the optical gap of single crystals arises from indirect transitions. (AU)

• FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
• Grantee: Munir Salomao Skaf
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 13/14065-7 - A First-Principles Study of Electronic, Structural, and Transport Properties of Clathrates for Thermoelectric Applications
• Grantee: Robert Luis González Romero
• Support Opportunities: Scholarships in Brazil - Post-Doctoral