1. Department of Materials Science and Engineering, Hanyang University, Seoul, 133-791, South Korea 2. Department of Materials Science and Engineering, Korea National University of Transportation, Chungbuk, 380-702, Korea
Abstract:
Li+/Tm3+/Yb3+ co-doped CaMoO4 upconversion (UC) phosphor was prepared by complex citrate-gel method and UC luminescence properties were investigated. Li+/Tm3+/Yb3+ co-doped CaMoO4 has intense blue emission induced by 1G4??3H6 transition at 476?nm that is improved 10 times more than that of Li+ undoped sample and weak red emission at 647 nm generated by 3F2??3H6 transition under excitation at 980?nm. The optimum doping concentration of Li+ ions was investigated and UC mechanism of Li+/Tm3+/Yb3+ co-doped CaMoO4 was discussed in detail.