Far-red-emitting Li6SrLa2Sb2O12: Mn4+ phosphor for plant growth LEDs application. (January 2021)

• Record Type: Journal Article
• Authors: Yan, Zhiwen; Yang, Xiaoliang; Xiao, Siguo
• Is Part Of: Materials research bulletin. Volume 133(2021)
• Publication Date: 2021-01
• Subjects: Li6SrLa2Sb2O12 -- Garnet-like -- Phosphors -- Far red-emitting -- Plant growth; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2020.111040
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: Far-Red emission of Mn 4+ in Li6 SrLa2 Sb2 O12 is observed for the first time. Mn 4+ doped Li6 SrLa2 Sb2 O12 can convert both UV and blue-green light into Far-Red emission peaking at 705 nm. The Li6 SrLa2 Sb2 O12 : Mn 4+ phosphor well meets the application of plant growth. The crystal field strength (Dq ) around Mn 4+ ions in Li6 SrLa2 Sb2 O12 host is 1996 cm −1 . Abstract: Novel far-red emission Li6 SrLa2 Sb2 O12 : Mn 4+ garnet-like phosphors have been synthesized via traditional high-temperature solid-state reaction method. The as-prepared Li6 SrLa2 Sb2 O12 : Mn 4+ phosphor has a broad excitation band in the range of 300−600 nm with four Gaussian fitting bands peaking at around 325 nm, 364 nm, 429 nm and 501 nm, respectively. It gives far-red emission peaking at 705 nm under both UV and blue-green excitation. The optimum doping concentration of Mn 4+ is about x = 0.01 and beyond which the luminescence quenching takes place, caused by the dipole-dipole interaction induced energy transfer among the Mn 4+ ions. When the temperature is raised up to 370 K, the emission intensity of Li6 SrLa2 Sb2 O12 : 0.01 Mn 4+ drops to 50 % of that at room temperature. The investigation shows that Li6 SrLa2 Sb2 O12 : Mn 4+ is a potential red phosphor matching NUV LED chips for plant growth application.