Modulation of Bi luminescence from broadband green to broadband deep red in LuWO by Gd doping and its applications in high color rendering index white LED and near-infrared LED.

Phosphors that exhibit tunable broadband emissions are highly desired in multi-functional LEDs, including pc-WLEDs and pc-NIR LEDs. In this work, broadband emissions were obtained and modulated in the unexpectedly wide spectral range of 517-609 nm for (LuGdBi)WO phosphors by tuning the Gd content ( = 0-0.99). The effects of Gd doping on phase constituents, particle morphology, crystal structure, and photoluminescence were systematically investigated. Broadband green emission was obtained from Gd-free (LuBi)WO phosphors ( = 0), whose emission intensity was enhanced by 50% with 5 at% Gd ( = 0.05). The phase transition happened when > 0.50 and the broadband red-NIR emission was obtained when = 0.75-0.99. Three luminescence centers were proved to be responsible for the broadband green emissions crystal structure, spectral fitting and fluorescence decay analysis. A pc-WLED with a high color rendering index ( = 91.3), a stable emission color, and a low color temperature (3951 K) was fabricated from the (LuGdBi)WO broadband green phosphor, and an LED device that simultaneously emits high color rendering index white light and NIR light was obtained with the (GdBi)WO broadband red-NIR phosphor. Night vision and noninvasive imaging were also demonstrated using the latter LED device.