Cr(III) and Eu(III) as doping ions in the Zn7Sb2O12 semiconductor: Investigation of structural and spectroscopic effects in the matrix.

• Grant number: 10/16401-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2010
• Effective date (End): December 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Ana Maria Pires
• Grantee: Josiane Aparecida Sobrinho
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil
• Associated research grant: 07/00880-0 - Rare earth luminescent nano reporters and probes, AP.JP

Abstract

Luminescent materials activated by transition metal ions and rare earth ions are particularly interesting due to their potential application that lies since solid state lasers under room temperature until high definition displays. Cr(III) ions are extensively investigated because interact efficiently with the matrix whereas they are located and show high luminescent quantum efficiency when doping host matrixes. Among trivalent rare earth ions (TR) that show characteristic f-f intraconfigurational emission in narrow lines pattern, europium is one of the most used activator in luminescent materials due to its exceptional spectroscopic properties. Because of their particular optical spectra, both Cr(III) and Eu(III) are also applied as spectroscopic probes for structural studies. In solids in general, the physical properties are related to point defects that arise in the formation of the compound in the host lattice by insertion of interstitial impurities. Factors such as composition, structure and morphology influence on the optical properties of luminescent materials for specific technological applications. AB2O4 spinel type structures, for example, have been widely studied for their possible use in various applications such as metallurgy, chemistry, catalysis and electronic industries. The zinc-antimony spinel Zn7Sb2O12 has been studied as a low voltage varistor and it is known to crystallize in the inverse spinel structure. In the ceramic form Zn7Sb2O12 shows interesting applications based on their semiconducting properties. The purpose of this work is to study on the semiconductor Zn7Sb2O12 obtained by the Pechini modified method doped with Cr(III) and Eu(III) ions at different concentrations in order to optimize the luminescent process. Also, it is the aim to investigate on the evidence of possible sites occupied by the doping ions in the host matrix and the influence of these ions in the structural and electrical semiconductor features.