The novel Er3+ and Yb3+ doped transparent Sialon ceramics were fabricated by hot pressing sintering method as a near infrared (NIR) as well as visible luminescent material. The optical transmittance, down-conversion luminescence and NIR luminescence were investigated. The samples show around 30% transmittance in visible region whereas 70% in IR region around 3000 nm. The samples were excited within the range of 350-400 nm wavelength, the highest emission was in green region (~ 550 nm). Also, the upconversion luminescence depending upon the thicknesses of the samples in the green and red region have been investigated. The NIR luminescence was observed around 1524 nm wavelength under 980 nm wavelength irradiation. The decay time profiles have been investigated for higher Er3+ concentration and higher Yb3+ co-doped with Er3+ α-Sialon samples. In this study, the addition of Yb3+ has poor sensitizing effect on Er3+ ion to enhance the luminescence.

Keywords: α-Sialon, NIR luminescence, Hot press, Transmittance.