Violet -light -excitable super -narrow band green emitting phosphor for high -quality white LEDs

Violet-light-based (390–420 nm) white LEDs are emerging as high-quality lighting devices for indoor lighting and more vivid display, in which the use of narrow-band phosphors would be beneficial for the improvement of maximum accessible color gamut, color rendering index (CRI) and visual luminous efficiency (LE). The nature of 4f electronic configuration of Tb3+ ion enables efficiently narrow-band green emission but suffering from inefficient light absorption in violet light region. Here, violet-light-excitable Tb3+ luminescence is realized in Ce3+-doped garnet Ca2TbZr2Al3O12 (CTZA) via efficient energy transfer (ET) from Ce3+ to Tb3+, providing dominant green emission originating from 5D4-7F5 transition with super-narrow full width at half maximum (FWHM) of only 9.74 nm and high internal quantum yield (QY = 60%). The performance of the white LEDs using CTZA:Ce3+ is studied, showing high CRI of 90.1, low correlated color temperature (CCT) of 3686 K and a wide color gamut of 61% of National Television System Committee standard (NTSC) in Commission Internationale de L'Eclairage (CIE) 1931 color space, which suggests its great potential for violet-based white LEDs. © 2020 Elsevier B.V.