Incorporation of Zn2+ ions into Al2O3:Er3+/Yb3+ transparent ceramics: An effective way to enhance upconversion and near infrared emission

Al2O3:Er3+/Yb3+ transparent ceramics codoped with Zn2+ ions with intense upconversion and near infrared emission were prepared by conventional solid-state reaction and vacuum and hot isostatic pressing sintering. The effects of Zn2+ incorporation to the structure, transparent, upconversion and NIR luminescence were discussed in detail. The as prepared Al2O3 ceramics exhibited a total transmittance of similar to 75% in infrared regions (800-3300 nm) and similar to 50% in visible regions (500-800 nm). Under the excitation of a 980 nm laser diode, the as prepared Al2O3 ceramics displayed two tense upconversion emission peaks of a green one centered at 550 nm and a red one centered at 660 nm and a tense near infrared emission peak centered at 1.532 mu m, characteristic of Er3+ emission. Compared with Er3+/Yb3+ doped only, Zn2+ codoped Al2O3: Er3+/Yb3+ transparent ceramics showed higher upconversion and near infrared emission of similar to 11 times and similar to 4 times, respectively. The enhancement mechanism due to incorporation of Zn2+ ions was also discussed in detail.