In:
Journal of Materials Chemistry C, Royal Society of Chemistry (RSC), Vol. 11, No. 25 ( 2023), p. 8462-8469
Abstract:
An efficient Cr 3+ -activated broadband near-infrared (NIR) phosphor is the key enabler to integrate compact NIR light-emitting diodes (pc-LEDs) for food testing and medical detection applications. High luminescence efficiency is key for the practical applications of phosphors. Herein, we design a series of efficient Cr 3+ -doped Ca 3 Al 2− y Sc y Ge 3 O 12 garnet phosphors to induce octahedral distortion for enhancing NIR luminescence efficiency. We adopt the best fitted ideal polyhedron to characterize the octahedral distortion and found that the degree of distortion reaches its maximum at y = 0.2 and decreases with y deviating from 0.2. As a result, the composition with y = 0.2 shows the highest luminescence intensity. The composition dependence of the octahedral distortion coincides with that of the luminescence intensity, indicating that the luminescence properties of Ca 3 Al 2− y Sc y Ge 3 O 12 :Cr 3+ are closely related to the octahedral distortion. The luminescence internal/external quantum efficiency (IQE/EQE) is significantly enhanced from 65.4%/25.7% in Ca 3 Al 2 Ge 3 O 12 :0.04Cr 3+ to 85.4%/33.5% in Ca 3 Al 1.8 Sc 0.2 Ge 3 O 12 :0.04Cr 3+ . The optimal Ca 3 Al 1.8 Sc 0.2 Ge 3 O 12 :0.04Cr 3+ phosphor exhibits excellent luminescence thermal stability (∼91% at 423 K) and high NIR output power (38.2 mW at 100 mA) with an electro-optical conversion efficiency of 13.7%. This work provides a strategy for enhancing the NIR luminescence of Cr 3+ .
Type of Medium:
Online Resource
ISSN:
2050-7526
,
2050-7534
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2023
detail.hit.zdb_id:
2702245-6
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