Band gap engineering of semiconductors chalcogenides

• Grant number: 14/25924-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2015
• End date: February 28, 2017
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Juarez Lopes Ferreira da Silva
• Grantee: Rafael Besse
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The development of materials with certain mechanical properties, electronic, optics, magnetic, etc., have great importance for the development technologic. By example, there is great interest in the development of new semiconductor materials certain electronic properties (band gap, conductivity, absorption coefficients) that can be changed in a controlled manner by changing the composition. In this context, in the recent years the synthesis of ternary and quaternary chalcogenides have attracted great attention due to the possibility of controlling the energy gap by replacing anions cations. For example, quaternary compounds, Cs2M II IV Q8 M3, M II = Mg, Zn, Cd, Hg; IV M = Ge, Sn, and Q = S, Se, Te, allow to obtain compounds gap energy between 1.0 eV and 4.0 eV, and thus, open the possibility for a variety of applications technologic. Although the number of possible compounds is very large, does not necessarily mean that all the compounds can be synthesized in the laboratory successfully. For example, the 24 possible compounds Cs2M II to IV M3 Q8, only 11 were synthesized compounds experimentally in laboratorythorium to date, that is, there are great challenges in the synthesis process beyondcosts involved in the process. Currently, computer simulations of first principles (ab initio) based on quantum mechanics (density functional theory), implementedin modern computer codes, have the potential to contribute to the development new materials. In this master's project, we propose the use of computed simulation based on density functional theory to the study and development of quaternary chalcogenides. (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)

BESSE, RAFAEL; DA SILVA, JUAREZ L. F.. The role of the alkali and chalcogen atoms on the stability of the layered chalcogenide A(2)M(II)M(3)(IV)Q(8) (A = alkali-metal; M = metal-cations; Q = chalcogen) compounds: a density functional theory investigation within van der Waals corrections. JOURNAL OF PHYSICS-CONDENSED MATTER, v. 29, n. 3, JAN 25 2017. (14/25924-3)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BESSE, Rafael. Study of the structural, energetic, electronic and optical properties of quaternary chalcogenides A2MIIMIV3Q8. 2017. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) São Carlos.