EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
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2023
·Vol. 26
·期 35
·e202300556
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IF 2.3
Quwei Ni,Jiansheng Huo,Qijian Zhu,Jianbang Zhou,Wenjie Sun,Yutong Huang,Chenggang Long,Qianming Wang
Graphical The Ca3Sc2Ge3O12:Cr3+ NIR emission garnet phosphor exhibits broadband emission peaking at 817 nm with a FWHM value of 128 nm. The developed phosphor presents balanced comprehensive performance and is suitable for NIR-LED application. The rapid growth in phosphor-converted near-infrared light-emission diodes (NIR-LEDs) has led to the development of NIR emitter with high efficiency, broadband emission and high thermal stability. In this work, an efficient broad NIR emission of Cr 3+ in novel Ca 3 Sc 2 Ge 3 O 12 (CSGO) garnet-based host was developed for the first time, which located at 700 to 1000 nm peaking at 817 nm with a broad bandwidth of ~128 nm. Such a broadband NIR emission originated from the preferential occupancy of Cr 3+ in Sc 3+ sites with weak octahedral field, which was manifested by the luminescence spectrum and decay behaviors. The Cr 3+ -doping concentration was regulated to achieve a good internal quantum efficiency (IQE) of 72.1 % and a fantastic thermal stability (at 423 K, sustained approximately 85 % of the initial intensity). The mechanism for concentration and thermal quenching was further investigated. Benefiting from the excellent luminescence features, a prototype NIR-LEDs was assembled via integrating the optimized samples with commercial blue InGaN LED chips, which exhibited a satisfactory photoelectric property and a brilliant performance in night vision. These results demonstrated the as-obtained sample to be a great potential candidate for NIR-LEDs.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 31
·11791-11802
·
IF 4.052
Baochen Wang,Ruiyu Mi,Yangai Liu,Ming Yu,Zhaohui Huang,Minghao Fang
The luminescence spectra of some trivalent rare-earth ions in a garnet host present interesting multisite structures; however, their mechanism is still not fully understood. In this study, for the first time, we directly observed two luminescence centers of Ce3+ at a single site in a novel garnet Ca3Sc2Ge3O12 phosphor. The spectral characteristics of the two luminescence centers were clearly identified using site-selective and time-resolved spectroscopy. Luminescence excitation was observed at 425 nm and 450 nm, corresponding to emissions at 490 (Ce(I)) nm and 530 (Ce(II)) nm. The decay curves confirmed the existence of energy transfer from Ce(I) to Ce(II). The potential mechanisms of the multisite luminescence are also discussed. This study gives a new insight into the concentration-dependent red-shift and inhomogeneous broadening of the Ce3+ emission band in the garnet phosphor. The title phosphor showed excellent thermal stability, with more than 90% of the initial intensity at the functioning temperature (323 K). Finally, a white LED lamp was fabricated, which exhibited an excellent color rendering index (82.3) and a proper correlated color temperature (3582 K). These results demonstrate that Ca3Sc2Ge3O12:Ce3+ is highly promising to serve as a blue-pumped phosphor for white LEDs.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 27
·9291-9299
·
IF 6.4
Yining Wang,Mengmeng Shang,Yixin Sun,Minliang Deng,Xiaole Xing,Peipei Dang,Jun Lin
With the increasing demand for the application of near-infrared (NIR) spectroscopy in security, agriculture, medical and other fields, people have been seeking efficient and intelligent NIR light sources. Herein, Cr3+ doped Ca3Sc2Ge3O12 (CSGG) broadband NIR phosphors are successfully synthesized. Under excitation of 480 nm, the emission peak of CSGG:Cr3+ is located at 785 nm, and the full width at half maximum (FWHM) is 106 nm. Low photoluminescence spectra (7 K and 77 K) support the broadband NIR emission coming from two Cr3+ luminescence centers occupying ScO6 and CaO8 sites, respectively. CSGG:Cr3+ exhibits excellent thermal stability (97% at 100 °C) and low internal quantum efficiency (IQE = 22%). The introduction of Ce3+ leads to the enhancement of IQE from 22% to 61% due to the following two reasons: the energy transfer from Ce3+ to Cr3+ and the lattice distortion which improves the parity forbidden transition of Cr3+. The mechanism of excellent luminescence thermal stability is revealed from the following perspectives: thermal activation energy, the Huang–Rhys factor and the thermal ionization effect. Benefiting from the excellent performance of CSGG:Cr3+,Ce3+ NIR phosphors, the combination with blue light chips demonstrates their potential applications in night vision security, biological imaging, and nondestructive testing.
研究领域:
材料科学
·
光学
·
生物医学工程
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DOI
高影响因子
CHINESE JOURNAL OF STRUCTURAL CHEMISTRY
·
2026
·
IF 10.5
Xingyu Li,Jian Peng,Zihao Xu,Wanyuan Li,Biao Xu,Chunyu Li,Wubin Dai
Simultaneous realizations of high thermal stability and quantum efficiency (QE) in phosphors with near-infrared (NIR) photoluminescence (PL) and long-persistent PL (LPL) attributes are a daunting task. Herein, we have come up with a dual-site co-substitution scheme in Ca 3 Sc 2 Ge 3 O 12 : Cr 3+ /Ni 2+ to concurrently actualize high-quality NIR-I/II (L)PL via either equivalent or aliovalent co-substitution at indirect lattice A/C sites of [Y 3+ + Al 3+ ] or [Y 3+ + Si 4+ ] for [Ca 2+ + Ge 4+ ]. Both Cr 3+ and Ni 2+ are colonized at B site (Sc 3+ ) under weak crystal field environment and emitting continuous PL across NIR-I/II regions via energy transfer from Cr 3+ to Ni 2+ under blue-light excitation. Due to inequivalent replacement of Ni 2+ at Sc 3+ site and consequential production of defects, a charming NIR LPL is also gained. Further incorporation of [Y 3+ + Al 3+ ] unit begets densified robust framework with [Sc(Cr/Ni)O 6 ] octahedral distortion, elucidating the mechanism of improved properties in PL QE (76.23%) and stability (89.5%@423 K). While [Y 3+ + Si 4+ ] modulation in Ca 3 Sc 2 Ge 3 O 12 not only brings rigid structure but also suppresses defects (LPL) because of equivalent triple-unit between Y 3+ /Si 4+ /Ni 2+ and Ca 2+ /Ge 4+ /Sc 3+ . A NIR pc-LED based on the designed phosphor with a commercial 460 nm blue LED chip is fabricated and reveals multi-applications in nondestructive detection, bioimaging, and anticounterfeiting. This work provides new perspectives for developing high-performance NIR-emitting phosphor materials. This study reveals the state-of-the-art researches on both NIR-I/II-emitting (L)PL phosphors with high QE and thermal stability from Cr/Ni-activated in garnet Ca 3 Sc 2 Ge 3 O 12 and their multiple applications in the NIR pc-LED, non-destructive detection, and anticounterfeiting. The proposed A/C-site regulation and ET from Cr to Ni pave a new way to design NIR-I/II phosphor and expands their related optoelectronic applications. Download: Download high-res image (298KB) Download: Download full-size image
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DOI
高影响因子
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