Broadband excited Na3Tb(PO4)2:Ce3+/Eu2+ green/yellow‐emitting phosphors with high color purity for LED‐based application. Issue 11 (19th July 2021)

• Record Type: Journal Article
• Authors: Huang, Shuai; Yu, Lixin; Peng, Kangliang; Zhao, Youjun; Wang, Jindi; Shang, Mengmeng
• Is Part Of: Journal of the American Ceramic Society. Volume 104:Issue 11(2021)
• Page Start: 5848
• Page End: 5858
• Publication Date: 2021-07-19
• Subjects: broad excitation band of Tb3+ -- high color purity -- narrow‐band emission -- orthophosphate -- white LEDs; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.17969
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: To enhance the display quality of light‐emitting diodes (LEDs), it is of great significance to exploit green/yellow‐emitting phosphors with narrow emission band, high quantum yield, and excellent color purity to satisfy the application. Herein, orthophosphate‐based green/yellow‐emitting Na3 Tb(PO4 )2 :Ce 3+ /Eu 2+ (NTPO:Ce 3+ /Eu 2+ ) phosphors have been successfully synthesized by a facile solid‐state reaction method. The absorption band of NTPO samples was extended to the near‐ultraviolet region and the absorption efficiency was significantly improved owing to a highly efficient energy transfer from Ce 3+ /Eu 2+ ion to Tb 3+ ion in NTPO host certified by time‐resolved PL spectra. Upon 300 nm excitation, the NTPO:Ce 3+ is characterized by ultra‐narrow‐band green emission of Tb 3+ with an absolute quantum yield of 94.5%. Unexpectedly, NTPO:Eu 2+ emits bright yellow light with a color purity of 73% as a result of the blending of green light emission from Tb 3+ and red light emission from Eu 3+ . The thermal stability has been improved by controlling the stoichiometric ratio of Na + . The prototype white LED used yellow‐emitting NTPO:Eu 2+ phosphor has higher color‐rendering index (Ra = 83.5), lower correlated color temperature (CCT = 5206 K), and closer CIE color coordinates (0.338, 0.3187) to the standard white point at (0.333, 0.333) than that used green‐emitting NTPO:Ce 3+ phosphor, indicating the addition of the yellow light component improved the Ra of the trichromatic (RGB) materials. Abstract : Broadband excited Na3 Tb(PO4 )2 :Ce 3+ /Eu 2+ green/yellow‐emitting phosphors with high color purity for LED‐based application