Very Intense Distinct Blue and Red Photoluminescence Emission in MgTiO3 Thin Films Prepared by the Polymeric Precursor Method: An Experimental and Theoretical Approach

Author(s)

Vetter Ferri, Elidia Aparecida ^[1] ; Mazzo, Tatiana Martelli ^[2] ; Longo, Valeria Moraes ^[3] ; Moraes, Eduardo ^[2] ; Pizani, Paulo Sergio ^[4] ; Li, Maximo Siu ^[5] ; Martinez Espinosa, Jose Waldo ^[6] ; Varela, Jose Arana ^[3] ; Longo, Elson ^[3]

Affiliation

^[1] Univ Tecnol Fed Parana, Dept Quim, BR-85503390 Pato Branco, PR - Brazil

^[2] Univ Fed Sao Carlos, Dept Quim, LIEC, INCTMN, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Estadual Paulista, Inst Quim, LIEC, INCTMN, BR-14800900 Araraquara, SP - Brazil

^[4] Univ Fed Sao Carlos, Dept Fis, Semicond Lab, BR-13565905 Sao Carlos, SP - Brazil

^[5] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13569970 Sao Paulo - Brazil

^[6] Univ Fed Goias, Dept Engn Prod, BR-75704020 Catalao, Go - Brazil

• Document type: Journal article
• Source: Journal of Physical Chemistry C; v. 116, n. 29, p. 15557-15567, JUL 26 2012.
• Web of Science Citations: 13

Abstract

MgTiO3 (MTO) thin films were prepared by the polymeric precursor method with posterior spin-coating deposition. The films were deposited on Pt(111)/Ti/SiO2/Si(100) substrates and heat treated at 350 degrees C for 2 h and then heat treated at 400, 450, 500, 550, 600, 650 and 700 C for 2 h. The degree of structural order disorder, optical properties, and morphology of the MTO thin films were investigated by X-ray diffraction (XRD), micro-Raman spectroscopy (MR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) measurements, and field-emission gun scanning electron microscopy (FEG-SEM) to investigate the morphology. XRD revealed that an increase in the annealing temperature resulted in a structural organization of MTO thin films. First-principles quantum mechanical calculations based on density functional theory (B3LYP level) were employed to study the electronic structure of ordered and disordered asymmetric models. The electronic properties were analyzed, and the relevance of the present theoretical and experimental results was discussed in the light of PL behavior. The presence of localized electronic levels and a charge gradient in the band gap due to a break in the symmetry are responsible for the PL in disordered MTO lattice. (AU)

• FAPESP's process: 98/14324-0 - Multidisciplinary Center for Development of Ceramic Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC