Bright red upconversion luminescence from Er3+ and Yb3+ co-doped ZnO-TiO2 composite phosphor powder. Issue 16 (November 2017)

• Record Type: Journal Article
• Authors: Kobwittaya, Krisana; Oishi, Yushi; Torikai, Toshio; Yada, Mitsunori; Watari, Takanori; Luitel, Hom Nath
• Is Part Of: Ceramics international. Volume 43:Issue 16(2017)
• Page Start: 13505
• Page End: 13515
• Publication Date: 2017-11
• Subjects: Upconversion -- ZnO-TiO2 composite -- Erbium -- Ytterbium; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.07.056
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: ZnO-TiO2 composites co-doped with Er 3+ and Yb 3+ ions were successfully synthesized by powder-solution mixing method and their upconversion (UC) luminescence was evaluated. The effect of firing temperature, ZnO/TiO2 mixing ratio, and dopant concentration ranges on structural and UC luminescence properties was investigated. The crystal structure of the product was studied and calculated in detail by means of X-ray diffraction (XRD). Also, the site preference of Er 3+ and Yb 3+ ions in the host material was considered and analyzed based on XRD results and UC luminescence characteristics. Brightest UC luminescence was observed in the ZnO-TiO2 :Er 3+, Yb 3+ phosphor fired at 1300 °C in which the system consisted of mixed phases; Zn2 TiO4, TiO2, RE2 Ti2 O7 and RE2 TiO5 (RE = Er 3+ and/or Yb 3+ ). Under the excitation of a 980 nm laser, the two emission bands were detected in the UC emission spectrum, weak green band centered at 544 and 559 nm, and strong red band centered at 657 and 675 nm wavelengths in accordance with 2 H11/2, 4 S3/2 → 4 I15/2 and 4 F9/2 → 4 I15/2 transitions of Er 3+ ion, respectively. The simple chemical formula equations, for explaining the site preference of Er 3+ and Yb 3+ ions in host crystal matrix, were generated by considering the Zn2 TiO4 crystal structure, its crystal properties, and the effect of Er 3+ and Yb 3+ ions to the host crystal matrix. The UC emission intensity of the products was changed by varying ZnO/TiO2 mixing ratios, and Er 3+ and Yb 3+ concentrations. The best suitable condition for emitting the brightest UC emission was 1ZnO:1TiO2 doped with 3 mol% Er 3+, 9 mol% Yb 3+ fired at 1300 °C for 1 h.