Achievement of broadband near-infrared phosphor Ca3Y2Ge3O12:Cr3+, Ce3+ via energy transfer for food analysis

Design, luminescence properties and applications of Cr3+-doped ScTaO4: a broadband near-infrared phosphor

“…Because the exchange interaction can occur only when the distance between the activating ions is less than 5 Å, 23 the reason for the concentration quenching of activating ions may be the electric multipole energy transfer. 24…”

“…Because the exchange interaction can occur only when the distance between the activating ions is less than 5 Å, 23 the reason for the concentration quenching of activating ions may be the electric multipole energy transfer. 24 According to the Dexter theory, the electric multipole interaction of the activating ion can be expressed by the following formula:…”

Highly efficient and thermally stable broadband near-infrared emitting garnet Ca3Sc2Ge3O12:Cr3+,Ce3+ phosphors for multiple pc-LED applications

“…The entry of Cr 3+ into the dodecahedra has been reported in La 3 Ga 5 GeO 14 and Ca 3 Y 2 Ge 3 O 12 . 20,30 The correspondence between the two Gaussian peaks and the luminescence center sites can be distinguished by local crystal field strength. Since the crystal field intensity of octahedrons is stronger than that of dodecahedrons, the Cr 3+ emission in the octahedron is closer to a shortwave direction.…”

“…29 Cui et al reported that the energy transfer efficiency between Ce 3+ and Cr 3+ in Ca 3 Y 2 Ge 3 O 12 was as high as 94.21%, and successfully applied it to non-destructive food detection. 29,30 Therefore, the NIR luminescence efficiency of Cr 3+ in garnet structure (A 3 B 2 C 3 O 12 ) could be easily improved by energy transfer using Ce 3+ as a sensitizer. On the other hand, a distorted crystal field environment is introduced to break through the limitation of the parity forbidden transition of Cr 3+ and thus improve the NIR luminescence efficiency.…”

Improving the luminescence thermal stability of Ca3Y2Ge3O12:Cr3+ based on cation substitution and its application in NIR LEDs

“…The results showed that Cr 3+ replaces Y 3+ and Ca 2+ , and the emission intensity of 0.01 Cr 3+ was the highest among the different Cr 3+ concentrations. 18 Mao et al also synthesized CYG:Cr 3+ phosphors and studied their luminescence properties and luminescence thermal stability. 19 Zhao et al 20 and Liu et al 21 reported the cation substitution method to improve the thermal stability of near-infrared luminescence.…”