Achieving the potential multifunctional near-infrared materials Ca₃In_2−xGa_xGe₃O₁₂:Cr³⁺using a solid state method

Abstract

Near-infrared spectroscopy is developing rapidly in the fields of human detection and food analysis due to its fast response and non-invasive characteristics.

Energy-saving chromium-activated garnet-structured phosphor-converted near-infrared light-emitting diodes

“…Ca 3 Ga 2 Ge 3 O 12 :Cr 3+ has three centered emission peaks at 749, 803, and 907 nm, while Ca 3 In 2 Ge 3 O 12 :Cr 3+ also possesses two distinct luminescent centers at 810 and 900 nm. 36,37 Mg 3 Y 2 Ge 3 O 12 also possesses three luminescent centers at 748, 806, and 899 nm. 38 It is assumed that the broadband NIR luminescence in germanate is due to the occupation of Cr 3+ in both the dodecahedral and octahedral environments.…”

“…46 At high temperatures, phosphor photoluminescence can be thermally quenched via thermal activation or thermal ionization mechanisms. 37 Thermal activation occurs when electrons in the excited state increasingly vibrate at high temperatures and cross the potential barrier between the ground and excited states, resulting in nonradiative relaxation to the ground state. The difference in energy between 2 E g and/or 4 T 2g and 4 A 2g influences thermal activation and is commonly represented as activation energy (DE).…”

Luminescence properties of Cr3+-doped near-infrared emissive fluoroyttrates for light-emitting diodes

“…According to Dexter's energy transfer theory, θ = 6 corresponds to electric dipole-dipole interactions, whereas θ = 3 represents the energy transfer among the nearest or next-nearest Cr 3+ activators. 38,39 Therefore, the concentration quenching mechanism in RNYF:Cr is presumably attributed to the energy transfer between the nearest or nextnearest Cr 3+ activators. The spectra shown in Fig.…”

Near-Infrared Emitting Phosphor LaMg0.5(SnGe)0.5O3:Cr3+ for Plant Growth Applications: Crystal Structure, Luminescence, and Thermal Stability

“…They can absorb NIR light and convert the inorganic salts in the environment into amino acids and nucleotides that are easy for plants to absorb, thus promoting the biological nitrogen fixation of plants and promoting plant growth. 5 In addition, it is found that when red and deep-red light are irradiated together, the growth rate of plants is much greater than the sum of their respective irradiation rates, which is known as the Emerson effect. 6 PC-LED, a combination of phosphors and LED chips, has promoted the development of lighting technology.…”

“…Photosynthetic bacteria, which are widely found in soil, play an important role in plant growth, especially in roots. They can absorb NIR light and convert the inorganic salts in the environment into amino acids and nucleotides that are easy for plants to absorb, thus promoting the biological nitrogen fixation of plants and promoting plant growth . In addition, it is found that when red and deep-red light are irradiated together, the growth rate of plants is much greater than the sum of their respective irradiation rates, which is known as the Emerson effect …”