White Upconversion Luminescence of Nd3+–Yb3+ Ion Pair Co-Doped Ex Situ Sol–Gel Synthesized Zinc-Silicate Dense Glass

Herein, we present white upconversion luminescence (UCL) of Nd3+ and Yb3+ ion co-doped Zinc-Silicate dense glass (SZNY-DG) for near-infrared excitation which was prepared through an ex situ sol–gel synthesis route. UCL of as-synthesized SZNY-DG sample was obtained because of possible sensitization of Yb3+ ion through 980 nm diode laser and further transfer of energy from the Yb3+ ion to nearby Nd3+ ion. The CIE 1931 chromaticity diagram was obtained for the UC sample based on PL emission to analyze and confirm the white light emission. The PL confocal microscopy was also reported to confirm the spatially resolved PL mapping. Thus, the present as-synthesized SZNY-DG sample exhibits its viability by producing highly efficient white light throughout the surface, when it was excited by a diode laser of wavelength ⁓980 nm.