Development of deep red–emitting CaBiVO₅:Pr³⁺ phosphor for multifunctional optoelectronic applications

Abstract

Orthorhombic Pr 3+ -doped calcium bismuth vanadate (CBV: Pr 3+ ) phosphors have been synthesized successfully via a citrate-gel method. The single-phase formation of CBV: Pr 3+ phosphor has been endorsed by X-ray diffraction (XRD) analysis. The scanning electron microscopy (SEM) image reveals dense-particle packaging with the quasi-spherical shape for the prepared CBV: Pr 3+ phosphors. Under blue light excitation, CBV: Pr 3+ phosphors exhibit intense red emission bands located at 608 and 656 nm wavelengths, overlapping with the absorption spectrum of P R phytochrome, which is present in plants. To achieve the maximum red intensity, the Pr 3+ ion concentration is optimized to be 1.25 mol% in the CBV host, after which the emission intensity ceases due to concentration quenching. Dexter's theory disclosed the possibility of d-d multipolar interaction among Pr 3+ ions at higher concentrations of Pr 3+ ions in the CBV host. The CIE coordinates are found to be positioned in the pure red region for CBV: Pr 3+ phosphor and in the proximity of red-emitting commercial phosphor. The temperature-dependent spectral studies manifest substantial thermal stability of the as-synthesized phosphor. All the studies mentioned above specify the tremendous potentiality of thermally stable CBV: Pr 3+ phosphor in agricultural lighting and w-LED applications. K E Y W O R D Sagricultural lighting, citrate gel, energy transfer, phytochrome, vanadate | 5765 KAUR And JAYASIMHAdRI the capability of controlling spectral composition via phosphor coated over the LED chip. [7][8][9] The emission from pc-LED matching well with plant photoreceptors (P R and P FR ) can offer ideal production in plant growth systems. Besides this, pc-LED delivers numerous advantages over prevailing lighting sources (incandescent, metal halide, and high-pressure lamps) such as environmental protection, improved energy efficiency, smaller size, advanced control capabilities, longer service time, and reduced radiated heat. [10][11][12] In general, pc-LEDs fabricated by coupling with FR-emitting Mn 4+ -doped phosphors and other red phosphors may exhibit an emission overlapped with the absorption spectrum of phytochromes. Such fabricated pc-LEDs can aid to control the duration of sunlight sensed by plants, which can regulate the flowering time of plants. 2,5,[13][14][15] Therefore, it is of great significance to develop eco-friendly phosphors-emitting red light under n-UV/blue light excitation for promoting regulated plant growth.Recently, numerous red phosphors incorporating rareearth (RE) ions (Eu 3+ and Sm 3+ ) have been investigated, which possess excellent chemical, thermal, and physical stabilities along with intense emission corresponding to the intra-4f transitions. 12,[16][17][18] But, there are only a few reports on Pr 3+ -doped red-emitting materials and their application for artificial lighting in plant growth systems. Such red luminescent material can additionally be applied in various fields, such as solar cells, white (w)-LEDs, fingerprint sensing, biologica...

UV‐excited blue‐ to green‐emitting Tb3+‐activated sodium calcium metasilicate colour tunable phosphor for luminescence devices

“…As the estimated value of is much larger than 5 Å , the multipolar interaction will take place in the NCMS:xTb 3+ phosphor, whereas the exchange interaction takes place when the value of is less than 5 Å , as per Van Uitert. [ 52,53 ]…”

Machine learning the peak emission wavelength of Mn4+-activated inorganic phosphors

“…The number of oxides belonging to the hexagonal system is sixteen, and the peak emission wavelength is around B660 nm or B690 nm. 4. The peak emission wavelengths of aluminates are between 651 and 731 nm, but it is more likely to be located at B660 nm and B710 nm.…”

“…Recently, transition metal Mn 4+ activated inorganic phosphors showing very narrow red emission have attracted tremendous attention owing not only to fundamental interest, but also to application prospects in indoor lighting and agriculture, biomedical, data communication and signal transmissions, and so forth. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Mn 4+ ions, acting as an activator, show broad absorption bands in the ultraviolet and blue region (200-600 nm) resulting from the 4 A 2g -4 T 1g , 2 T 2g , 4 T 2g transitions and emit red light (600-780 nm) owing to the 2 E g -4 A 2g transitions, while it situates in a host material with octahedral sites. 16,17 Their emission behavior is heavily affected by their local chemical coordination, host matrix composition, and their inherent crystallographic distortions, activator concentrations, and the energy transfer mechanisms involved.…”

Emission enhancement in the luminescence performance of warm red light‐emitting LiSrVO4:Pr3+ phosphors

“…Using DR spectra and the Kubelka-Munk function [22], the band gap values were calculated to be 3.69 and 3.71 eV for the undoped and…”