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

Abstract

Near infrared phosphor Ca3-xSrxY2Ge3O12:Cr3+ was synthesized by the solid-state method. When Sr2+ substituted for Ca2+, the thermal stability of the phosphor is obviously improved, and the emission intensity, at 150...

Advances in Chromium‐Activated Phosphors for Near‐Infrared Light Sources

“…The strategy of crystallographic site engineering has been applied in many materials to improve the luminescence property such as LaSc 2.93‐ y Ga y B 4 O 12 :0.07Cr 3+ (0 ≤ y ≤ 1.5), LaSc 3‐ x Y x B 4 O 12 :Cr 3+ (0 ≤ x ≤ 1.3), Na 3 X 2 Li 3 F 12 :Cr 3+ (X = Al, Ga, and In), Ca 3 In 2‐ x Ga x Ge 3 O 12 :0.07Cr 3+ ( x = 0–2), Ca 3‐ x Sr x Y 2 Ge 3 O 12 :Cr 3+ , etc. [ 99,103,189,190,303 ]…”

Multicolor tunable bright photoluminescence in Ca2+/Mg2+ modified Eu3+ doped ZnGa2O4 phosphors under UV excitation for solid state lighting applications

“…The FWHM of the 613 nm peak in the case of ZnGa 2 O 4 :0.1Eu 3+ phosphor decreases rapidly while in the case of ZnGa 2 O 4 :0.1Eu 3+ /3Ca 2+ phosphor it decreases slowly. 29 Fig. 15(a and b) shows the variation in FWHM of the peaks in the ZnGa 2 O 4 :0.1Eu 3+ and ZnGa 2 O 4 :0.1Eu 3+ /3Ca 2+ phosphors as a function of temperature supplied to the samples.…”

“…14(a and b), the PL emission intensity of Eu 3+ bands reduces continuously with the rise in temperature due to thermal quenching effect. [29][30][31][32][33] The emission intensity of 613 nm emission band is reduced upto 58.43% and 64.88% at 423 K for the ZnGa 2 O 4 :0.1Eu 3+ [see Fig. 14(c)] and ZnGa 2 O 4 :0.1Eu 3+ /3Ca 2+ [see Fig.…”

“…The variation of PL emission intensity with temperature is a function of thermal stability of the phosphor materials. 29 The thermal stability of phosphor samples are compared in terms of photoluminescence emission at 423 K (150 °C) for LEDs applications as the phosphor materials deteriorate at higher temperatures and reduce its emission efficiency. 30 The temperature dependent PL intensity has been studied by Rajendran et al in Ba 2 YV 3 O 11 :Eu 3+ phosphor and found the thermal stability of phosphor is 59.5% at 423 K. 31 In the case of Ba 2 LaV 3 O 11 :Eu 3+ , this value was reported to be 62% at 423 K. 32 The temperature-dependent PL in the Bi 4 Si 3 O 12 :Eu 3+ phosphor was also studied by Zhang et al 33 They have found that the PL emission intensity is decreased to 50% at 398 K compared to its PL intensity at 298 K. It would be interesting to measure the thermal stability of Eu 3+ doped and Eu 3+ /Ca 2+ co-doped ZnGa 2 O 4 phosphor material.…”

Highly‐Efficiency Far‐Red Emission in Cr3+ Activated Ca1.8Mg1.2Al2Ge3O12 toward Plant Precise Lighting

“…[21] Li et al prepared Ca 3-x Sr x Y 2 Ge 3 O 12 :Cr 3+ phosphors by substituting Ca 2+ with Sr 2+ , which led to improved thermal stability. [22] Guo et al improved the emission of Cr 3+doped Mg 7 Ga 2 GeO 12 spinel system phosphors by introducing alkali earth metals (Ca, Sr, Ba) to replace Mg 2+ , thereby increasing lattice distortion. [23] In this study, based on Ca 3 Al 2 Ge 3 O 12 :Cr 3+ , [24] Mg 2+ was introduced to replace Ca 2+ , and a series of Ca 3-x Mg x Al 1.97 Ge 3 O 12 :0.03Cr 3+ (C 3-x M x AGG:0.03Cr 3+ ) phosphors were successfully synthesized using a high-temperature solid-phase method.…”