Choi, Heechae Cho, So Hye Khan, Sovann Lee, Kwang-Ryeol Kim, Seungchul 2024-01-20T09:03:33Z 2024-01-20T09:03:33Z 2021-09-02 2014-08-14 2050-7526 https://pubs.kist.re.kr/handle/201004/126469 Bi3+ as a dopant in wide-band-gap yttria (Y2O3) has been used as a green light emission center or a sensitizer of co-doped rare earth elements. Because the photoluminescence (PL) properties of Y2O3:Bi3+ vary remarkably according to heat treatment, the roles of point defects have been an open question. By using first-principles calculations and thermodynamic modeling, we have thoroughly investigated the formation of point defects in Y2O3:Bi3+ at varying oxygen partial pressures and temperatures, as well as their rotes in PL. The photoabsorption energies of the Bi3+ dopant were predicted to be 3.1 eV and 3.4 eV for doping at the S-6 and the C-2 sites, respectively, values that are in good agreement with the experimental values. It was predicted that an oxygen interstitial (01) and an oxygen vacancy (V-O) are the dominant defects of Y2O3:Bi3+ at ambient pressure and an annealing temperature of 1300 K (3.19 x 10(16) cm(-3) for 1% Bi doping), and the concentrations of these defects in doped Y2O3 are approximately two orders of magnitude higher than those in undoped Y2O3. The defect V-O(2+) in Y2O3:Bi3+ was predicted to reduce the intensity of PL from Bi3+ at both S-6 and C-2 sites. We verify our computational predictions from our experiments that the stronger PL of both 410 and 500 nm wavelengths was measured for the samples annealed at higher oxygen partial pressure. English ROYAL SOC CHEMISTRY GENERALIZED GRADIENT APPROXIMATION LUMINESCENCE PROPERTIES TRANSPARENT CERAMICS PERFORMANCE PHOSPHORS OXIDE BI3+ Roles of an oxygen Frenkel pair in the photoluminescence of Bi3+-doped Y2O3: computational predictions and experimental verifications Article 10.1039/c4tc00438h 1 JOURNAL OF MATERIALS CHEMISTRY C, v.2, no.30, pp.6017 - 6024 JOURNAL OF MATERIALS CHEMISTRY C 2 30 6017 6024 scie scopus 000339471100005 2-s2.0-84904197824 Materials Science, Multidisciplinary Physics, Applied Materials Science Physics Article GENERALIZED GRADIENT APPROXIMATION LUMINESCENCE PROPERTIES TRANSPARENT CERAMICS PERFORMANCE PHOSPHORS OXIDE BI3+ photoluminescence Y2O3 first principles calculations Bi doping Oxygen pressure annealing