White light-emitting Dy3+-doped transparent chloroborosilicate glass: synthesis and optical properties

ABSTRACT Dy3+-doped chloroborosilicate glasses with the composition 35.7SiO2–25.5B2O3–17BaO–3.4K2O–3.4Al2O3–15BaCl2 (mol%) were prepared using melt quenching technique. The glass transition temperature (Tg) was ~610°C. In UV–vis–NIR absorption spectra, characteristic absorption bands of Dy3+ appeared at 322, 347, 364, 388, 795 and 880 nm due to spectral transitions from the 6H15/2 level to various higher levels of Dy3+ ion. The excitation spectrum was recorded at within 200–550 nm by monitoring emissions at 576 nm. The excitation bands at 392, 428, 453 and 472 nm were attributed to the 6H15/2 → 4I13/2, 4G11/2, 4I15/2 and 4F9/2 transitions, respectively. Prominent emission bands were observed at wavelengths of 484, 576, 664 and 754 nm when excited at 447 nm. The bands correspond to the transitions 4F9/2 → 6H15/2, 4F9/2 → 6H13/2, 4F9/2 → 6H11/2 and 4F9/2 → 6H9/2 6F11/2, respectively. The emitted light from all the samples was found to be white. Their color coordinates lie within the white range. The sample containing 0.5 wt% Dy2O3 emitted white light with the color coordinates x = 0.351, y = 0.335, which are the very closest to pure white light and whose color temperature of 4716 K is similar to daylight. Such white light-emitting transparent glasses promise to be enormously useful for various photonic applications