Materials Today Physics
·
2024
·
IF 10
Daiyuan Liu,Ru Zhao,Chao Wang,Zhichao Liu,Jian Zhang,Yuan Wang,Xue Yu,Jianbei Qiu,Xuhui Xu,Yichun Liu
High-quality phosphors with color tunability are urgently needed for the full-spectrum white light-emitting diodes (WLEDs) with healthy and comfortable lighting like the solar spectrum. Here, a Sr 2 Ga 2 SiO 7 : Eu 2+ phosphor with tunable luminescence color is reported, achieving a luminescence tuning from maize-yellow to yellow by changing the Eu 2+ ion concentration. Importantly, the quantum efficiency of BaSrGa 2 SiO 7 : 1.0 % Eu 2+ is as high as 85.7 % compared with 49.1 % of Sr 2 Ga 2 SiO 7 : 5.0%Eu 2+ , and the emission intensity of BaSrGa 2 SiO 7 : 1.0 % Eu 2+ retains 92 % of the room temperature (RT) emission intensity at 473 K by Ba 2+ substitution. Furthermore, the increase of Ba 2+ ion concentration also makes the phosphor achieve tunability from yellow to green. The as-prepared full-spectrum WLEDs exhibits a continuity spectrum like solar spectrum with an extremely high color rendering index of 93.5 and low correlated color temperature of 4562 K. This work provides new insights into the exploration of new phosphors for high-performance full-spectrum WLEDs devices.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Pengju Xia,Wanyuan Li,Kaiting Wu,Yifeng Lei,Wubin Dai
In the process of studying newfangled phosphor-converted white-light-emitting diodes (pc-wLEDs), some basic and important objectives of phosphor, i.e., high chemical/thermal stability, color rendering index (CRI), and low correlated color temperature (CCT), should pass muster simultaneously. Herein, for the first time, a series of photoluminescence (PL) color-tunable single-phase Ca3Y(GaO)3(BO3)4: Dy3+/Sm3+/La3+ (CYGB: Dy/Sm/La) phosphors with good dispersivity, crystallinity, and size uniformity have been designed and synthesized via a facile solid-state reaction method. Structurally, based on XRD and Rietveld refinements, the tendentious occupations of Dy/Sm/La on the Y3+ site with a 9-coordinated number (CN) over other cationic sites are in line with the facts that the ionic radius and charge difference of Dy/Sm/La are much closer to Y3+ in 9-CN than Y3+ in 7-CN and Ca2+ in both 9- and 7-CN. Spectrally, thanks to the “cool” white PL from 4f–4f transitions of Dy and red-emitting from Sm, polychromatic PL including “warm” white light with high efficiency could be realized in CYGB: Dy/Sm via the regulation of doping content and energy transfer (ET). Intriguingly, the “abnormal” phenomena of zero-thermal-quenching in the range from room temperature (RT) to 573 K were observed, probably owing to the synergistic effects of electron–phonon coupling, ET, and structural defects. Moreover, by tridoping La3+ to legitimately adjust the site environments, the PL of both Dy/Sm could be further tuned because they all include hypersensitive transitions that are closely related to the crystal field environment. Finally, as a proof-of-concept fabrication, the pc-wLED assembled by a combination of the composition-optimized CYGB: Dy/Sm/La and an n-UV LED chip via remote “capping” packaging shows attractive performances, indicating its potential as an efficient phosphor for n-UV wLEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-8
·
IF 3.125
Segovia Rubén,Qu Geyang,Peng Miao,Sun Xiudong,Shi Hongyan,Gao Bo
Self-assembled organic-inorganic CH 3 NH 3 PbI 3 perovskite microwires (MWs) upon humidity exposure along several weeks were investigated by photoluminescence (PL) spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). We show that, in addition to the common perovskite decomposition into PbI 2 and the formation of a hydrated phase, humidity induced a gradual PL redshift at the initial weeks that is stabilized for longer exposure (~ 21 nm over the degradation process) and an intensity enhancement. Original perovskite Raman band and XRD reflections slightly shifted upon humidity, indicating defects formation and structure distortion of the MWs crystal lattice. By correlating the PL, Raman, and XRD results, it is believed that the redshift of the MWs PL emission was originated from the structural disorder caused by the incorporation of H 2 O molecules in the crystal lattice and radiative recombination through moisture-induced subgap trap states. Our study provides insights into the optical and structural response of organic-inorganic perovskite materials upon humidity exposure.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 4
·585-589
·
IF 0.875
Wei Qi,Wang Liyuan
Molecular glass resist has been considered as one of the best choices for a new generation of lithography. In this work, a new type of photoactive compound was obtained by the esterification of tannic acid with 2-diazo-1-naphthoquinone-4-sulfonyl chloride(2,1,4-DNQ-Cl) and ditertbutyl dicarbonate. The new obtained compound possessed both a photosensitive group of diazonaphthoquinone sulfonate(2,1,4-DNQ) and a group of acidolytic protection. Upon the irradiation of the compound under 365 nm light, the former group was photolyzed and converted into indene carboxylic acid along with a small amount of sulfonic acid, which could lead to the deprotection of the latter group. As a result, a novel i-line molecular glass photoresist was formed with the chemical modification of tannic acid. The experimental results show that the modificated compound had a fair solubility in many organic solvents. The lithographic performance of the resist was evaluated on an i-line exposure system with high photosensitivity and resolution as well.
研究领域:
材料科学
·
微纳加工
·
高分子化学
·
光电子学
·
半导体工艺
✓ 已验证
DOI
高影响因子
Small
·
2022
·Vol. 18
·期 18
·2107145
·
IF 15.153
Jiong Li,Chenghao Duan,Qiaoyun Wen,Ligang Yuan,Shibing Zou,Chang Chen,Weiguang Xie,Dongxu Lin,Christopher C. S. Chan,Kam Sing Wong,Keyou Yan
Integrating highly efficient photovoltaic (PV) function into light-emitting diodes (LEDs) for multifunctional display is of great significance for compact low-power electronics, but it remains challenging. Herein, it is demonstrated that solution engineered perovskite nanocrystals (PNCs, ≈100 nm) enable efficient electroluminescence (EL) and PV performance within a single device through tailoring the dispersity and interface. It delivers the maximum brightness of 490 W sr −1 m −2 at 2.7 V and 23.2% EL external quantum efficiency, a record value for near-infrared perovskite LED, as well as 15.23% PV efficiency, among the highest value for nanocrystal perovskite solar cells. The PV–EL performance is well in line with the reciprocity relation. These all-solution-processed PV-LED devices open up viable routes to a variety of advanced applications, from touchless interactive screens to energy harvesting displays and data communication.
研究领域:
材料科学
·
纳米技术
·
光电子学
·
能量收集
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 40
·21452-21459
·
IF 8.867
Yunxia Li,Peng Miao,Wei Zhou,Xiao Gong,Xiujian Zhao
Luminescent solar concentrators (LSCs) have been widely studied because of their potential importance in industry. A variety of luminescent materials have been developed and used for LSC fabrication such as organic dyes and semiconductor quantum dots. However, fabricating LSCs with a cost-effective method and environmentally friendly materials is a great challenge. Here, N-doped carbon-dots (N-CDs) are for the first time reported to be used as phosphors for LSC fabrication. The properties of N-CDs/PMMA thin film LSCs with various thicknesses are investigated. When the N-CDs/PMMA thin film thickness is 6.67 μm and only one side of LSCs is covered by photovoltaic cells, the performance of the LSCs is optimal, and the values of Voc, Jsc, FF, ηopt and η can reach up to 0.46 V, 13.68 mA cm−2, 62.89%, 4.75% and 3.94%, respectively. Moreover, the photostability of the LSCs is excellent. Results show that N-CDs are able to be effective luminophores for LSC fabrication. Our technique makes the industrial applications of LSCs more feasible since N-CDs have advantages such as high stability, low cost, low toxicity and high photoluminescence quantum yield.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Yao Pei,Ran Wang,Xiang Rong,Xiang Xia,Hexiang Wang,Zongwei Zhang,Tian Qiu,Saran Long,Jianjun Du,Jiangli Fan,Wen Sun,Xiaojun Peng
ABSTRACT The key factor in photothermal therapy lies in the selection of photothermal agents. Traditional photothermal agents generally have problems such as poor photothermal stability and low photothermal conversion efficiency. Herein, we have designed and synthesized an isoindigo (IID) dye. We used isoindigo as the molecular center and introduced common triphenylamine and methoxy groups as rotors. In order to improve the photothermal stability and tumor targeting ability, we encapsulated IID into nanoparticles . As a result, the nanoparticles exhibited high photothermal stability and photothermal conversion efficiency (67%) upon 635 nm laser irradiation. Thus, the nanoparticles demonstrated a significant inhibitory effect on live tumors in photothermal therapy guided by photoacoustic imaging and provided a viable strategy to overcome the treatment challenges.
研究领域:
生物医学工程
·
肿瘤学
·
材料科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 14
·7712-7719
·
IF 6.895
Yongsheng Zhu,Jun Zhao,Gang Yang,Xiumei Xu,Gencai Pan
Lead halide perovskite nanocrystals (PNCs) have very recently emerged as promising emitters for their superior optoelectronic properties. However, the defects in perovskite itself make it susceptible to the external environment and internal ion migration, resulting in low photoluminescence quantum yield (PLQY) and poor device efficiency. Herein, we developed a method to reduce the surface defects of PNCs by introducing ammonium acetate in the synthesis of CsPbI3 PNCs. The addition of ammonium acetate can effectively eliminate undesired surface metallic lead cations and dangling bonds, resulting in an enhanced PLQY and stability. The passivated PNCs have an overall up-shift energy level, demonstrating better hole injection efficiency. As a result, the red light-emitting diodes (LEDs) fabricated with the passivated CsPbI3 PNCs achieved an optimal EQE of 10.6% and a maximum brightness of 981 cd m−2, which are 3.1 and 2.4 times that of unpassivated PNCs based devices, respectively.
研究领域:
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Fengping Ruan,Degang Deng,Ming Wu,Bowen Chen,Lei Lei,Ruoshan Lei,Shiqing Xu
A novel dual-emitting Ca 8 ZrMg(PO 4 ) 6 (SiO 4 ): (Eu 3+ , Eu 2+ ) phosphors with ultrahigh-sensitive optical temperature sensing are prepared by a conventional solid-state method. The Eu 2+ /Eu 3+ co-activated Ca 8 ZrMg(PO 4 ) 6 (SiO 4 ) phosphors exhibit efficient dual-mode emissions with an intense, broad blue emission peaked at 414 nm and a relative bright red-emitting centered at 614 nm under 297 nm UV-light excitation, respectively. Furthermore, the fluorescence intensity ratio (FIR) technology is applied to analyse the optical temperature sensing performance of Ca 8 ZrMg(PO 4 ) 6 (SiO 4 ): (Eu 3+ , Eu 2+ ) phosphors. Based on different thermal quenching behavior of Eu 2+ and Eu 3+ dual-emitting centers, linear temperature-dependent FIR between Eu 2+ and Eu 3+ is obtained. The maximal absolute sensitivity reaches as high as 5.94% K −1 , which is superior to that for the other luminescent temperature sensing materials reported previously. Analyses of the temperature-dependent photoluminescence spectra and configurational coordinate diagrams for Ca 8 ZrMg(PO 4 ) 6 (SiO 4 ): (Eu 3+ , Eu 2+ ) phosphors indicate that the temperature-sensitive variation in FIR of Eu 2+ to Eu 3+ is originated from the difference in thermal quenching activation energy for 5d→4f transition of Eu 2+ and 5 D 0 → 7 F J (J = 1, 2, 4) transitions of Eu 3+ . These results reveal that the Ca 8 ZrMg(PO 4 ) 6 (SiO 4 ): (Eu 3+ , Eu 2+ ) phosphors show glorious potential in high temperature optical thermometry.
研究领域:
材料科学
·
无机化学
·
光学传感
·
功能材料
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Yanting Zhu,Chenxia Li,Degang Deng,Hua Yu,Hao Li,Le Wang,Changyu Shen,Xufeng Jing,Shiqing Xu
A series of Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor was synthesized by traditional high temperature solid stated method, and the temperature-sensitive characteristic of the phosphor was researched. Due to the temperature sensitivity of the fluorescence lifetime of Cr 3+ , the thermometry based on fluorescence lifetime can be realized. Furthermore, the emissions of Eu 2+ ion and Cr 3+ ion can be well separated, which shows the excellent signal recognition ability of this phosphor. The Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor can be used for the thermometry based on fluorescence intensity ratio. A dual-mode optical thermometry is proposed and researched in the temperature range of 293–563 K by using the decay lifetime of Cr 3+ emission and in the temperature range of 295–476 K by using the fluorescence intensity ratio of Eu 2+ to Cr 3+ as temperature readout. The maximum values of relative sensitivity are 0.466% K −1 at 363 K and 0.259% K −1 at 476 K. The Eu 2+ /Cr 3+ co-doped BaAl 12 O 19 phosphor has excellent optical temperature characteristic , and its dual-mode thermometry characteristics provide convenience for the application of this material. This phosphor has potential application prospects in the field of optical thermometry.
研究领域:
材料科学
·
光学工程
·
无机化学
·
传感器技术
·
功能材料
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 22
·2001037
·
IF 8.286
Dongjie Liu,Xiaohan Yun,Guogang Li,Peipei Dang,Maxim S. Molokeev,Hongzhou Lian,Mengmeng Shang,Jun Lin
Highly efficient cyan-emitting phosphor materials are indispensable for closing the cyan gap in spectra of the traditional phosphor-converted white light-emitting diodes (WLEDs) to achieve high-quality full-spectrum white lighting. In this work, bright cyan-emitting Ca 3 Ga 4 O 9 (CGO):0.02Bi 3+ ,0.07Zn 2+ phosphor is developed to bridge the cyan gap. Such a Bi 3+ ,Zn 2+ codoping enhances the cyan emission of CGO:0.02Bi 3+ by 4.1 times due to the influence of morphology and size of phosphor particles, charge compensation and lattice distortion. Interestingly, codoping La 3+ ions into the current system can achieve a photoluminescence tuning of CGO:0.02Bi 3+ from cyan to yellowish-green by crystallographic site engineering. Besides, Bi 3+ –Eu 3+ energy transfer is successfully realized in CGO:0.02Bi 3+ ,0.07Zn 2+ , n Eu 3+ phosphors and the emission color tuning from cyan to orange is observed. The investigation of thermal quenching behaviors reveals that the incorporation of Zn 2+ and La 3+ improves the thermal stability of CGO:0.02Bi 3+ . Finally, CGO:0.02Bi 3+ ,0.07Zn 2+ ,0.10Eu 3+ phosphor is employed to obtain a single-phased warm WLED device. A full-spectrum WLED device with remarkable color rendering index (Ra) of 97.4 and high luminous efficiency of 69.72 lm W −1 is generated by utilizing CGO:0.02Bi 3+ ,0.07Zn 2+ phosphor. This result suggests the important effect of CGO:0.02Bi 3+ ,0.07Zn 2+ phosphor on closing the cyan gap, providing new insights of cyan-emitting phosphors applied in full-spectrum white lighting.
研究领域:
材料科学
·
光学工程
·
固体物理
·
无机化学
·
光电子学
·
照明技术
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2022
·
IF 7.613
J. Du,S. Lyu,K. Jiang,D. Huang,J. Li,R. Van Deun,D. Poelman,H. Lin
Persistent luminescent materials containing deep-level traps have attracted extensive research interest in the field of optical information storage due to their unique features of long-lasting emission, energy storage, and controllable photon release upon external stimulations. However, the lack of suitable luminescent materials with deep-level traps is still the bottleneck of such an optical storage application. Herein, we report a series of persistent luminescent materials with reddish-orange emissions and controllable photon release upon thermal stimulation. Through substitution of Sn by Si, more and deeper trap levels are achieved in Sr 2 SnO 4 :Sm 3+ ,Si 4+ phosphors. Moreover, both ultraviolet light and high-energy X-ray irradiations can induce reddish-orange emitting persistent luminescence from the as-synthesized samples. Rewritable optical information storage and readout based on photon trapping and de-trapping processes are demonstrated. Optical information can be handily encoded using a commercially available 365 nm light-emitting diode, and decoded upon thermal stimulation. The Sr 2 SnO 4 :Sm 3+ ,Si 4+ phosphors as presented in this work show a great promise for rewritable optical data storage and information encryption.
研究领域:
材料科学
·
光功能材料
·
固态化学
·
信息存储技术
·
发光物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）