Enhancing photoluminescence properties of Mn⁴⁺‐activated Sr_4−xBa_xAl₁₄O₂₅ red phosphors for plant cultivation LEDs

Abstract

Non–rare earth Mn4+‐activated strontium aluminate phosphor is considered to be a promising material for plant cultivation field owing to their advantage of inexpensively, environment friendly, nontoxic, and appropriate spectral range. In this paper, a Sr4−xBaxAl13.99O25:0.01Mn4+,1.4H3BO3 strontium aluminate phosphor is synthesized by a convenient high‐temperature solid‐state reaction. The photoluminescence spectra located at red region with a peak at 655 nm in the range of 600 to 750 nm that can be excited under the excitation of ultraviolet (~346 nm) or blue light (~450 nm). The shape emission band at 655 nm is attributed to the transition of 2Eg‐4A2g. Furthermore, the emission intensity of Sr4−xBaxAl13.99O25: 0.01Mn4+,1.4H3BO3 phosphor is conducted in detail with the variety of Ba2+ doping concentration and the intensity can be enhanced to 140.9% than the Sr4Al13.99O25:0.01Mn4+,1.4H3BO3 when the value of Ba2+ concentration equal to 0.1 mol. In addition, the X‐ray diffraction spectra, element mapping, composition modifying, optical properties, FT‐IR spectra, diffuse reflectance spectra, thermal stability, and fluorescence lifetime are systematically investigated. According to the electro‐luminescent spectra of as‐packaged LED, indicating that the Sr3.9Ba0.1Al13.99O25:0.01Mn4+,1.4H3BO3 phosphor will become a great candidate for plant cultivation LEDs due to the emission spectra match well the plant pigment spectrum.

A Review On The Exploration Of The Red Phosphors For The Fabrication Of Phosphor-Converted-LEDs For Plant Growth In Indoor Farming

“…Han et al [13] doped Mn 4+ in tetratungstate Sr 9 Gd 2 W 4 O 24 (SGWO). The emission spectra under excitation at 355 nm emitted strong far-red emission at 694 nm ( 2 E g → 4 A 2g ), which matched well with the absorption spectra of phytochrome PFR.…”

Short review on recent progress in Mn4+‐activated oxide phosphors for indoor plant light‐emitting diodes

“…Wu et al . [ 40 ] modified the composition of the Sr 4 Al 14 O 25 host with Ba 2+ corporation. The boric acid was used as flux agent, which was also found to have an impact on the luminescent properties.…”

Theoretical calculations and photoluminescence properties of Sr4Al14O25:Mn4+ red phosphors doped with Li+

“…22 The spectrum emission corresponding to the 2 E-4 A 2g spin-forbidden transition is located in the narrow-band red region, and the two wider absorption peaks correspond to the spin-allowed transitions of 4 A 2g -4 T 2g and 4 A 2g -4 T 1g . [23][24][25] Then, the spin forbidden ring is easily broken by changing the symmetry of the lattice, and high-efficiency red light emission is obtained. The transition of 4 A 2g -4 T 2g is usually located in the blue-violet region, which can be matched with the blue chip.…”