Influence of Zn1-xCaxWO4 heterostructures synthesized by spray pyrolysis on photoluminescence property

Author(s)

Santiago, A. A. G. ; Fernandes, Y. L. R. L. ; Tranquilin, R. L. ; Longo, E. ; Paskocimas, C. A. ; Motta, F., V ; Bomio, M. R. D.

• Document type: Journal article
• Source: CERAMICS INTERNATIONAL; v. 45, n. 17, p. 9-pg., 2019-12-01.

Abstract

Tungstates are inorganic materials with great potential in diverse applications, mainly as a photoluminescent material as a candidate to replace traditional lighting sources. In this study, we report the synthesis and characterization of Zn1-xCaxWO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) powders with white light-emitting properties. Using X-ray diffraction, the formation of the monoclinic ZnWO4 phase was observed for x = 0 and the formation of the tetragonal scheelite phase of CaWO4 was observed for x = 1. The formation of a heterostructure composed of both phases was found for compositions with x = 0.2, 0.4, 0.6 and 0.8. Scanning electron microscopy images showed that the Zn1-xCaxWO4 particles exhibit a spherical morphology. The band-gap energies had variation between 3.79 eV and 3.99 eV, being influenced by the degree of structural disorder. The photoluminescence emission spectra of the samples showed white light emission. Thus, Zn1-xCaxWO4 can be considered as promising white light sources, mainly for the sample synthesized with x = 0.8 for application in LED lamps (6500 K). (AU)

• FAPESP's process: 16/23891-6 - Computer modeling of condensed matter
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants