12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone

Red emission of Pr3+ enhancement by addition of Ba2+ and In3+ in CaTiO3:Pr phosphor

13 Jul 2011, 17:00


Poster Presentation Track A - Condensed Matter Physics and Material Science Poster1


Mr Luyanda Lunga Noto (University of Free State (Student))


CaTiO3 exhibits a Perovskite structures that has an ABO3 stochiometry where A and B represent metal cations with a combined charge of 6+ valency and O with 6- valency, and thus bring about charge neutrality to the compound. Upon introducing Pr3+ ions in the site of Ca2+ ions, charge imbalance occurs by introducing a 7+ valency, and this force the material to compensate for this effect by introducing negative Ca & Ti vacancies, and positive O vacancies. These act by hampering the material luminescence. Thus substitution of Ti4+ by co-doping with Ba2+ and In3+ ions result into a 6+ valency and thus an electrically neutral compound. This reinforces the red emission of Pr3+ ions inside CaTiO3. CaTiO3: Pr3+ exhibiting red emission is synthesized via solid state reaction, and its luminescence is enhanced by co-doping with Ba2+ and In3+ that act as charge compensators. This optimal emission of CaTiO3:Pr3+,Ba2+,In2+ is achieved by solid state reaction at 1300 oC for 4h, by direct firing, according to 1:1 molar ratio of TiO2 Anatase and CaCO3 compounds, doping with 0.3 mol%Pr3+ (PrCl3) and charge compensating by adding In3+ (In(NO3)3) and Ba2+ (Ba(NO3)2).The observed 613 nm photoluminescence (PL) peak, when exciting the material with 330 nm ultraviolet light to promote (2p(O) → 3d (Ti)) absorption using the PL spectrometer, is attributed to the 1D2 → 3H4 transition of the Pr3+ ions. The glow curves were measured using Thermo luminescence (TL) spectroscopy. Addition of Ba2+ and In3+ ions into CaTiO3:Pr3+ phosphor enhances the optical performance of the Pr3+ red-emission. Additionally the phase was identified using the X-ray diffraction (XRD) and the surface morphology identified using Scanning Electron Microscopy (SEM).

Consider for a student <br> &nbsp; award (Yes / No)? Yes
Level (Hons, MSc, <br> &nbsp; PhD, other)? MSc
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? Yes

Primary author

Mr Luyanda Lunga Noto (University of Free State (Student))


Prof. HC Swart (University of Free State) Prof. JJ Terblans (University of Free State) Prof. OM Ntwaeaborwa (University of Free State) Dr Shreyas Pitale (University of Free State)

Presentation Materials