title: Effect of Pressure-Assisted Heat Treatment on Photoluminescence Emission of α-Bi2O3 Needles.
abstract: Materials with high photoluminescence (PL) intensity can potentially be used in optical and electronic devices. Although the PL properties of bismuth(III) oxide with a monoclinic crystal structure (α-Bi2O3) have been explored in the past few years, methods of increasing PL emission intensity and information relating PL emission to structural defects are scarce. This research evaluated the effect of a pressure-assisted heat treatment (PAHT) on the PL properties of α-Bi2O3 with a needlelike morphology, which was synthesized via a microwave-assisted hydrothermal (MAH) method. PAHT caused an angular increase between the [BiO6]-[BiO6] clusters of α-Bi2O3, resulting in a significant increase in the PL emission intensity. The Raman and XPS spectra also showed that the α-Bi2O3 PL emissions in the low-energy region (below ∼2.1 eV) are attributed to oxygen vacancies that form defect donor states. The experimental results are in good agreement with first-principles total-energy calculations that were carried out within periodic density functional theory (DFT).
authors.affiliation: Department of Physical Chemistry, UNESP-Institute of Chemistry , 14800-060 Araraquara, SP Brazil.
authors.forename: Samara
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: Department of Materials Engineering, State University of Ponta Grossa , 84030-900 Ponta Grossa, PR Brazil.
authors.forename: Evaldo T
authors.initials: ET
authors.lastname: Kubaski
authors.affiliation: Department of Chemistry and Environmental Sciences, UNESP-IBILCE , 15054-000 São José do Rio Preto, SP Brazil.
authors.forename: Diogo P
authors.initials: DP
authors.lastname: Volanti
authors.affiliation: Department of Production Engineering, Federal University of Technology-Paraná , 84016-210 Ponta Grossa, PR Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: Sequinel
authors.affiliation: Department of Physical Chemistry, UNESP-Institute of Chemistry , 14800-060 Araraquara, SP Brazil.
authors.forename: Vinicius Danilo N
authors.initials: VD
authors.lastname: Bezzon
authors.affiliation: Departament de Química Física i Analítica, Universitat Jaume I , Campus del Riu Sec, E-12071 Castelló de la Plana, Spain.
authors.forename: Armando
authors.initials: A
authors.lastname: Beltrán
authors.affiliation: Department of Chemistry, State University of Ponta Grossa , 84030-900 Ponta Grossa, PR Brazil.
authors.forename: Sergio M
authors.initials: SM
authors.lastname: Tebcherani
authors.affiliation: Department of Physical Chemistry, UNESP-Institute of Chemistry , 14800-060 Araraquara, SP Brazil.
authors.forename: José A
authors.initials: JA
authors.lastname: Varela