Electronic excitations in cubic fluorite crystals within different computational schemes: CaF2, BaF2 and CdF2 as test cases

• Grant number: 16/12105-0
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: October 01, 2016
• End date: October 11, 2016
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Marcelo Marques
• Grantee: Marcelo Marques
• Visiting researcher: Giancarlo Cappellini
• Visiting researcher institution: Università di Cagliari, Italy
• Host Institution: Divisão de Ciências Fundamentais (IEF). Instituto Tecnológico de Aeronáutica (ITA). Ministério da Defesa (Brasil). São José dos Campos , SP, Brazil

Abstract

The visit of Professor Giancarlo Cappellini of the University of Cagliare (UniCa) to the Group of Materials and Nanotechnology-GMSN of the Instituto Tecnológico de Aeronáutica-ITA aims to continue the scientific collaboration of the study of fluoride compounds such as BaF2, the CaF2, and CdF2, materials with electronic properties especially related to technological applications in the ultraviolet range of the electromagnetic spectrum. The research essentially involves calculating excited states using approximate models to include quasi-particle effects. These results are related to description of how these materials interact with electromagnetic radiation, a fundamental aspect of these technological applications. Professor Cappellini has extensive experience in the theoretical study of these compounds, as well as generally in the methodology employed in the description of excited states in semiconductors. In addition to the use of the method based on Pseudo-Self-Interaction Corrected density functional (VPSIC) recently developed by A. Filippetti and employees of the university of Cagliari, especially noteworthy in this collaboration the use of LDA-1/2 method developed by researchers of GMSN in collaboration with Prof. Luiz G. Ferreira da USP. The LDA-1/2 method due to its low computational cost allows the study of more complex and realistic systems as fluorides impurities and surfaces, very difficult to be calculated in the state of art GW method. We point out that we already have very promising initial results for the band structure of fluorides with the LDA-1/2 method. During his visit, and the development of research, systematic contacts with researchers and students from GMSN, Prof. Cappellini will teach the short course "excitons in semiconductors Calculation: study of Bethe-Salpeter equation." This topic is of great importance for the future steps of the collaboration, because these materials have a large energy gap and the effect of exciton in optical properties is, in many cases, essential. Furthermore, the GMSN has as one of its major subject of research study two-dimensional material in the exciton is also very important. The course will also be open to researchers from other institutions and thereby benefit not only the GMSN, like other groups in the region and neighboring towns. The visit will be widely publicized in advance, the site of the Brazilian Physics Society, the group's web page and the ITA. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MATUSALEM, FILIPE; MARQUES, MARCELO; TELES, LARA K.; FILIPPETTI, ALESSIO; CAPPELLINI, GIANCARLO. Electronic properties of fluorides by efficient approximated quasiparticle DFT-1/2 and PSIC methods: BaF2, CaF2 and CdF2 as test cases. JOURNAL OF PHYSICS-CONDENSED MATTER, v. 30, n. 36, SEP 12 2018. (16/12105-0)