High‐Power Broadband NIR LEDs Enabled by Highly Efficient Blue‐to‐NIR Conversion

Basore, Endale T.; Wu, Huajun; Xiao, Wenge; Zheng, Guojun; Liu, Xiaofeng; Qiu, Jianrong

doi:10.1002/adom.202001660

Cited by 81 publications

(79 citation statements)

References 45 publications

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“…[ 9 , 12 ] Instead, trivalent ytterbium ion (Yb 3+ ) is an excellent short‐wave NIR emitter, and its blue light excitation can be realized via the sensitization of Cr 3+ . [ 30 ] Thanks to the suitable Y 3+ sites for Yb 3+ occupation, the short‐wave NIR emission can be enriched by introducing Yb 3+ into YCAS:Cr 3+ (Figure S21 , Supporting Information). Moreover, YCAS:Cr 3+ ,Yb 3+ have ultrahigh IQE (>95%) and nearly zero thermal quenching (Figure S22 , Supporting Information), which is attributed to efficient energy transfer from Cr 3+ to Yb 3+ .…”

Section: Discussion and Outlookmentioning

confidence: 99%

“…Moreover, YCAS:Cr 3+ ,Yb 3+ have ultrahigh IQE (>95%) and nearly zero thermal quenching (Figure S22 , Supporting Information), which is attributed to efficient energy transfer from Cr 3+ to Yb 3+ . [ 30 ] Finally, we also anticipated that it is possible, though very challenging, for glass crystallization to achieve efficient Cr 3+ activated bulk materials with longer peak emission wavelength (>800 nm) as well as extra‐broad emission band, through rational design of the glass composition and fine control of the crystalline phases. [ 19 , 20 , 21 ]…”

Section: Discussion and Outlookmentioning

confidence: 99%

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Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

Zheng

Xiao

et al. 2022

Advanced Science

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Near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are newly emergent broadband light sources for miniaturizing optical systems like spectrometers. However, traditional converters with NIR phosphors encapsulated by organic resins suffer from low external quantum efficiency (EQE), strong thermal quenching as well as low thermal conductivity, thus limiting the device efficiency and output power. Through pressureless crystallization from the designed aluminosilicate glasses, here broadband Near‐infrared (NIR) emitting translucent ceramics are developed with high EQE (59.5%) and excellent thermal stability (<10% intensity loss and negligible variation of emission profile at 150 °C) to serve as all‐inorganic visible‐to‐NIR converters. A high‐performance NIR phosphor‐converted light emitting diodes is further demonstrated with a record NIR photoelectric efficiency (output power) of 21.2% (62.6 mW) at 100 mA and a luminescence saturation threshold up to 184 W cm−2. The results can substantially expand the applications of pc‐LEDs, and may open up new opportunity to design efficient broadband emitting materials.

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Section: Discussion and Outlookmentioning

confidence: 99%

Section: Discussion and Outlookmentioning

confidence: 99%

Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

Zheng

Xiao

et al. 2022

Advanced Science

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“…[ 14–20 ] In particular, Cr 3+ ‐doped phosphors have received increasing attention owing to their intrinsic broadband NIR emission and blue‐light excitation features. [ 21–23 ] Moreover, this type of emission can be realized by simply doping Cr 3+ ions into a weak octahedral crystal field environment. Therefore, several Cr 3+ activated phosphors for LEDs have been developed, [ 18,24–30 ] some of which exhibit high photoluminescence internal quantum efficiency (IQE) of >90%, such as Gd 3 Sc 2 Ga 3 O 12 :0.01Cr 3+ ,0.5Al 3+ (IQE = 98.6%), [ 31 ] Ca 3 Sc 2 Si 3 O 12 :0.06Cr 3+ (IQE = 92.3%), [ 32 ] and GdAl 3 (BO 3 ) 4 :0.01Cr 3+ (IQE = 91%).…”

Section: Introductionmentioning

confidence: 99%

A General Ammonium Salt Assisted Synthesis Strategy for Cr³⁺‐Doped Hexafluorides with Highly Efficient Near Infrared Emissions

Song

Zhou

et al. 2021

Adv Funct Materials

135

111

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The discovery of highly efficient broadband near infrared (NIR) emission material is urgent and crucial for constructing NIR lighting sources and emerging applications. Herein, a series of NIR emission hexafluorides A2BMF6:Cr3+ (A = Na, K, Rb, Cs; B = Li, Na, K, Cs; M = Al, Ga, Sc, In) peaking at ≈733–801 nm with a full width at half maximum (FWHM) of ≈98–115 nm are synthesized by a general ammonium salt assisted synthesis strategy. Benefiting from the pre‐ammoniation of the trivalent metal sources, the Cr3+ can be more efficiently doped into the A2BMF6 and simultaneously prevent the generation of the competitive phase. Particularly, Na3ScF6:Cr3+ (λem = 774 nm, FWHM ≈ 108 nm) with optimal Cr3+‐doping concentration of 35.96% shows a high internal quantum efficiency of 91.5% and an external quantum efficiency of ≈40.82%. A lighting emitting diode (LED) device with a NIR output power of ≈291.05 mW at 100 mA driven current and high photoelectric conversion efficiency of 20.94% is fabricated. The general synthesis strategy opens up new avenues for the exploration of Cr3+‐doped high efficiency phosphors, and the as‐obtained record NIR output power demonstrates for NIR LED lighting sources applications.

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“…Thus, numerous studies have been conducted to develop efficient FR phosphors and pc‐LEDs in recent three years. [ 6–26 ]…”

Section: Introductionmentioning

confidence: 99%

Cr³⁺ Activated Garnet Phosphor with Efficient Blue to Far‐Red Conversion for pc‐LED

Han

Zhang

et al. 2021

Advanced Optical Materials

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120

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Far‐red (FR) phosphor‐converted light‐emitting diodes (pc‐LEDs) driven by blue LED chips are novel light sources for applications in phototherapy, photosynthesis, natural light simulation, and so on but still bear low electricity‐to‐FR light conversion efficiency (≤ 23%) due to deficiency of phosphors that have both high blue light absorptance and high FR internal quantum efficiency (IQE) for the realization of efficient blue to FR conversion. FR Ca3Sc2Si3O12 (CSSG):Cr3+ garnet phosphor has ultra‐high IQE (> 90%) but low blue light absorption. Here, a twofold increase of blue light absorption cross‐section is reported with still high FR IQE via Lu3+−Mg2+ substitution for Ca2+−Sc3+ in CSSG:Cr3+ to form Ca3–xLuxMgxSc2–xSi3O12:Cr3+ garnet solid solution, which is attributed to enhanced mixing of odd‐parity configuration into 3d configuration of Cr3+ induced by the cations substitution. Optical properties, crystal field strengths, and thermal stabilities of the solid solution phosphors are studied as a function of x. After complete replacement of Sc3+, the as‐fabricated FR pc‐LED emits at 750 nm with 65.7% blue‐to‐FR quantum conversion efficiency and consequently offers an electricity‐to‐FR light conversion efficiency over 30%. Moreover, the solid solution phosphors show high quenching temperatures in the range of 580–610 K. The results can advance the development of efficient FR phosphors and pc‐LEDs for various applications.

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High‐Power Broadband NIR LEDs Enabled by Highly Efficient Blue‐to‐NIR Conversion

Cited by 81 publications

References 45 publications

Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

A General Ammonium Salt Assisted Synthesis Strategy for Cr³⁺‐Doped Hexafluorides with Highly Efficient Near Infrared Emissions

Cr³⁺ Activated Garnet Phosphor with Efficient Blue to Far‐Red Conversion for pc‐LED

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High‐Power Broadband NIR LEDs Enabled by Highly Efficient Blue‐to‐NIR Conversion

Cited by 81 publications

References 45 publications

Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

Glass‐Crystallized Luminescence Translucent Ceramics toward High‐Performance Broadband NIR LEDs

A General Ammonium Salt Assisted Synthesis Strategy for Cr3+‐Doped Hexafluorides with Highly Efficient Near Infrared Emissions

Cr3+ Activated Garnet Phosphor with Efficient Blue to Far‐Red Conversion for pc‐LED

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Product

Resources

About

A General Ammonium Salt Assisted Synthesis Strategy for Cr³⁺‐Doped Hexafluorides with Highly Efficient Near Infrared Emissions

Cr³⁺ Activated Garnet Phosphor with Efficient Blue to Far‐Red Conversion for pc‐LED