10.1021/acs.inorgchem.5b01237.s002 Samara Schmidt Samara Schmidt Evaldo T. Kubaski Evaldo T. Kubaski Diogo P. Volanti Diogo P. Volanti Thiago Sequinel Thiago Sequinel Vinicius Danilo N. Bezzon Vinicius Danilo N. Bezzon Armando Beltrán Armando Beltrán Sergio M. Tebcherani Sergio M. Tebcherani José A. Varela José A. Varela Effect of Pressure-Assisted Heat Treatment on Photoluminescence Emission of α‑Bi<sub>2</sub>O<sub>3</sub> Needles American Chemical Society 2015 XPS Bi PL emission intensity PAHT DFT 2O form defect donor states PL properties MAH 2015-11-02 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Effect_of_Pressure_Assisted_Heat_Treatment_on_Photoluminescence_Emission_of_Bi_sub_2_sub_O_sub_3_sub_Needles/2116003 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-Bi<sub>2</sub>O<sub>3</sub>) 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-Bi<sub>2</sub>O<sub>3</sub> with a needlelike morphology, which was synthesized via a microwave-assisted hydrothermal (MAH) method. PAHT caused an angular increase between the [BiO<sub>6</sub>]–[BiO<sub>6</sub>] clusters of α-Bi<sub>2</sub>O<sub>3</sub>, resulting in a significant increase in the PL emission intensity. The Raman and XPS spectra also showed that the α-Bi<sub>2</sub>O<sub>3</sub> 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).