INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Dan Zhang,Xiangting Zhang,Zhengce An,Rujia Dong,Zhan Shi,Yanhua Song,Haifeng Zou
Here, the crystal structure, phase analysis, site occupancy, and luminescence properties of NCMP:Eu2+,Tb3+,Mn2+ have been studied for the first time. Under 335 nm ultraviolet excitation, the NCMP:Eu2+ phosphors show narrow-band blue emission. In addition, we discuss the reason for a continuous red shift for the emission spectra of NCMP:xEu2+ by raising the x value. The efficient ET processes of Eu2+ → Tb3+ and Eu2+ → Mn2+ were investigated by the luminescence spectra and decay curves. The ET efficiencies reach 92.58% at y = 0.15 for NCMP:0.01Eu2+,yTb3+ and 99.85% at z = 0.15 for NCMP:0.01Eu2+,zMn2+ phosphors, respectively. The efficient energy transfer processes greatly improve the quantum efficiency, luminous intensity, and thermal stability. Bright green and red emissions can be realized through changing the related ratio of Eu2+, Tb3+, and Mn2+. In addition, the excellent performance of the prepared white LED lamps utilizing a 385 nm chip combined with our prepared NCMP:Eu2+,Tb3+/Mn2+ phosphors indicates that NCMP:0.01Eu2+,yTb3+ and NCMP:0.01Eu2+,zMn2+ phosphors can be potential green and red phosphors for white LEDs.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2015
·
IF 2.252
Hua Ye,Baofeng Zhao,Dongyun Li,Dongcheng Chen,Gaozhan Xie,Shi-Jian Su,Wei Yang,Yong Cao
A series of blue-light-emitting conjugated polymers based on electron-donating trifluoren-2-ylamine and electron-deficient dibenzothiophene- S,S -dioxide were synthesized via typical Suzuki coupling reactions. Their thermal, photophysical and electrochemical properties were fully studied. Owing to the excellent thermal stability, film-forming ability as well as the favorable energy levels of the polymers, highly efficient non-doped single-layer blue devices by using these polymers as an emitting layer (EML) were achieved. Among them, the device based on PSFOFN1 showed the highest maximum current efficiency (CE max ) of 1.99 cd/A. Moreover, the device presented small efficiency roll-off with current efficiency (CE) of 1.97 cd/A at high brightness up to 100 cd/m 2 . In addition, the Commission Internationale de L’Eclairage (CIE) coordinates of all the devices are very close to the deep blue region. Our findings suggest the potential applications of the polymers in full-color flat-panel displays and organic lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Nanoscale
·
2021
·Vol. 13
·期 8
·4562-4568
·
IF 7.79
Zhiwen Yang,Qianqian Wu,Xiaochuan Zhou,Fan Cao,Xuyong Yang,Jianhua Zhang,Wanwan Li
Environment-friendly high color purity blue zinc selenide (ZnSe) quantum dot-based light-emitting diodes (QLEDs) are promising candidates in next-generation display applications. However, due to the large bandgap of ZnSe (2.7 eV), the reported electroluminescence (EL) wavelengths of ZnSe QLEDs are mainly located within the range from purple to violet blue, and preparing blue emitting (>445 nm) ZnSe QLEDs remains challenging. Herein, we report a seed-mediated and double shell strategy to synthesize large-sized blue ZnSe/ZnS/ZnS core/shell/shell quantum dots (QDs). The as-prepared QDs possess excellent features including narrow full widths at half-maximum (11–19 nm), tunable emission wavelengths (410–451 nm), and high photoluminescence quantum yields (≥50%). Using ZnSe/ZnS/ZnS QDs as emitters in an inverted device, a color saturated blue QLED with an EL wavelength of 446 nm, a maximum luminance of 106 cd m−2, a current efficiency of 0.94 cd A−1, and an EQE of 2.62% is successfully fabricated. These results indicate that blue ZnSe QLEDs have great potential for future display technologies.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2019
·Vol. 3
·期 10
·2120-2127
·
IF 0
Qiang Zhang,Xicheng Wang,Zuobin Tang,Yuhua Wang
A novel blue-emitting phosphor, Na3ScSi2O7:Ce3+ (NSSO:Ce3+), was synthesized with a solid-state method at low temperature successfully. Its crystal structure, band structure, and photoluminescence and cathodoluminescence properties were researched in detail. The phase formation and the crystal structure were confirmed by powder X-ray diffraction analysis and the Rietveld refinement method, respectively. Under the excitation of n-UV light, the optimal NSSO:0.02Ce3+ phosphor can yield blue emission centered at 452 nm with a high quantum efficiency of 50.9%. The PL intensity of the NSSO:0.02Ce3+ phosphor remains at 71.46% of the initial value when the temperature is increased from room temperature to 150 °C, indicating good thermal stability. A WLED lamp was obtained by combining a 360 nm n-UV chip with Sr2SiO4:Eu2+, (Ca, Sr)AlSiN3:Eu2+ and NSSO:0.02Ce3+ phosphors, in which the color coordinates, CCT and CRI are (0.360, 0.348), 4409 K and 90.9, respectively. Moreover, under low voltage electron bombardment, the phosphor can emit blue emission with high luminescence intensity, current saturation and resistance. All the results indicate that the NSSO:Ce3+ phosphor shows much potential for the application of both WLEDs and field emission displays (FEDs). Our research has also offered a new insight and perspective that using Sc-based sorosilicates as host can be an appropriate strategy for developing excellent inorganic luminescence materials.
研究领域:
材料科学
·
光学工程
·
无机化学
·
固态照明
·
显示技术
✓ 已验证
DOI
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 24
·19477-19489
·
IF 2.779
Zhao Jianwen,Dong Jun,Zhou Jian,Wang Linsheng
White light-emitting diodes (WLEDs) are of paramount importance in the development of lighting and display in replace of inefficient fluorescence as well as incandescent lamps. In this work, Tb 3+ , and Tm 3+ were both introduced into a novel phosphate host Ca 9 Nd(PO 4 ) 7 . The X-ray diffraction (XRD) analyses make sure that the materials have been synthesized successfully. Further XRD Rietveld refinements were used to shed light on the site preference and the variations of crystal lattice parameters. Strong blue light emission was observed after careful optimization of the doping concentration. Theoretical computation on the basis of density functional theory checks the reliability of the phosphate host for doping luminescent centers. At last, a near-ultraviolet commercial LED chip was used with these materials to make a prototype WLED device. They possess a highly stable warm white light emission upon various driving currents (color temperature is constant 4000 K). The work has shown intriguing prospects of Ca 9 Nd(PO 4 ) 7 : Tm 3+ , Tb 3+ in lighting and display applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 17
·2200386
·
IF 10.05
Yue-Yue Ma,Yu-Ming Sun,Wen-Jie Xu,Xue-Lei Liu,Qian-Qian Zhong,Ying-Rui Song,Han-Qi Fu,Cheng-Yang Yue,Xiao-Wu Lei
Despite remarkable luminescent performance of 0D lead halide perovskites, achieving highly efficient blue light emission is extremely challenging and crucial for this domain. Considering the high toxicity of Pb 2+ ion, it is significant to explore water-stable lead-free 0D halides as highly efficient and stable blue emitting materials. To address these issues, a family of 0D hybrid zinc halides of AZnBr 4 (A = EP, BP, and TMPDA) based on discrete [ZnBr 4 ] 2− tetrahedrons is herein reported as desirable blue light emitters. The wide band gaps enable these 0D halides to display highly efficient blue light emissions (452–485 nm) with highest photoluminescence quantum yield (PLQY) of 35.47%. More importantly, all these 0D halides present extraordinary chemical stabilities in humid air and water for one month, and are also capable of withstanding extreme pH conditions in the range of 0–14, likely the widest observed pH range for perovskites. Notably, the ultrahigh chemical stabilities of 0D zinc halides are nearly unmatchable among all known literature perovskite materials to the best of the authors’ knowledge. Combined superiorities of unusual blue light emission, promising PLQY, ultrahigh stability, and non-toxicity highlight the potential optoelectronic applications in wide chemical environments for these 0D zinc halides.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Hua Ye,Denghui Liu,Fen Liu,Liangyuan Chen,Wei Hu,Yu Bai,Jiali Rao,Dehan Wu,Xinyi Cai,Shi-Jian Su
A series of light-emitting dendrimers T42Bn, T24Bn, T26Bn and T35Bn based on electron-donating units of the second-generation butyicarbazoles (G2Cz) as dendrons and electron-withdrawing core of tripyridylbenzene (TPB) were designed and synthesized. The desirable blue luminogens were obtained due to the rational molecular design based on the twisted skeleton of all the molecules despite the donors of G2Cz moieties connected to the central acceptors of TPB via a para-phenylene bridge. Their thermal, photophysical, density functional theory calculation and electrochemical properties were fully investigated. Thanks to the excellent thermal stability, film-forming ability as well as the favourable energy levels of the dendrimers, efficient solution-processed hybrid white organic light-emitting diodes (WOLEDs) were achieved by employing these blue dendrimers and the orange emitter of (acetylacetonato)-bis[2-(thieno [3,2-c]pyridin-4-yl)phenyl]iridium(III) (PO-01) as an emitting layer (EML). Among them, the device based on T42Bn exhibited the highest maximum current efficiency (CE max ) of 10.25 cd/A with a maximum external quantum efficiency (EQE max ) of 3.94% and Commission International de I'Eclairage (CIE) coordinates of (0.34, 0.39), benefiting from the largest ƞ PLQY and the highest electron transport capability of T42Bn and thus the enhancement of charge carrier balance in the device. In addition, the CIE coordinates of all the single-emitting-layer fluorescence/phosphorescence hybrid devices are very close to the benchmark white region of (0.33, 0.33). Our findings demonstrate the potential candidates of the solution-processable blue dendronized emitters for applications in full-color flat-panel displays and white lighting.
研究领域:
材料科学
·
光电化学
✓ 已验证
DOI
高影响因子
Advanced Science
·
2020
·Vol. 7
·期 20
·2001698
·
IF 15.84
Yujun Xie,Bo Peng,Ivona Bravić,Yan Yu,Yurong Dong,Rongqing Liang,Qiongrong Ou,Bartomeu Monserrat,Shuyu Zhang
Colloidal CsPbX 3 (X = Br, Cl, and I) perovskite nanocrystals exhibit tunable bandgaps over the entire visible spectrum and high photoluminescence quantum yields in the green and red regions. However, the lack of highly efficient blue-emitting perovskite nanocrystals limits their development for optoelectronic applications. Herein, neodymium (III) (Nd 3+ ) doped CsPbBr 3 nanocrystals are prepared through the ligand-assisted reprecipitation method at room temperature with tunable photoemission from green to deep blue. A blue-emitting nanocrystal with a central wavelength at 459 nm, an exceptionally high photoluminescence quantum yield of 90%, and a spectral width of 19 nm is achieved. First principles calculations reveal that the increase in photoluminescence quantum yield upon doping is driven by an enhancement of the exciton binding energy due to increased electron and hole effective masses and an increase in oscillator strength due to shortening of the Pb Br bond. Putting these results together, an all-perovskite white light-emitting diode is successfully fabricated, demonstrating that B-site composition engineering is a reliable strategy to further exploit the perovskite family for wider optoelectronic applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Advanced Science
·
2019
·Vol. 6
·期 13
·1900462
·
IF 15.804
Chenghao Bi,Shixun Wang,Stephen V. Kershaw,Kaibo Zheng,Tönu Pullerits,Sergey Gaponenko,Jianjun Tian,Andrey L. Rogach
Colloidal all-inorganic perovskite nanocrystals have gained significant attention as a promising material for both fundamental and applied research due to their excellent emission properties. However, reported photoluminescence quantum yields (PL QYs) of blue-emitting perovskite nanocrystals are rather low, mostly due to the fact that the high energy excitons for such wide bandgap materials are easily captured by interband traps, and then decay nonradiatively. In this work, it is demonstrated how to tackle this issue, performing self-assembly of 2D perovskite nanoplatelets into larger size (≈50 nm × 50 nm × 20 nm) cuboid crystals. In these structures, 2D nanoplatelets being isolated from each other within the cuboidal scaffold by organic ligands constitute multiple quantum wells, where exciton localization on potential disorder sites helps them to bypass nonradiative channels present in other platelets. As a result, the cuboid crystals show an extremely high PL QY of 91% of the emission band centered at 480 nm. Moreover, using the same synthetic method, mixed-anion CsPb(Br/Cl) 3 cuboid crystals with blue emission peaks ranging from 452 to 470 nm, and still high PL QYs in the range of 72–83% are produced.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
半导体物理
·
胶体化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Tao Hua,Yu-Chun Liu,Chih-Wei Huang,Nengquan Li,Changjiang Zhou,Zhongyan Huang,Xiaosong Cao,Chung-Chih Wu,Chuluo Yang
Highly efficient blue thermally activated delayed fluorescence (TADF) materials with high horizontal dipole orientation (Θ // ) remain a big challenge due to the concentration quenching effects and serious efficiency roll-offs in their corresponding organic light-emitting diodes (OLEDs). We herein report two novel TADF compounds, namely 2TDBA-SBA and TDBA-SBA, which were facilely synthesized by utilizing a rigid oxygen-bridged cyclized triarylboron-based unit (TDBA) as the acceptor and a spiro acridine (SBA) as the donor. Benefiting from the rigid and planar skeleton of the acceptor and the linear molecular shape, high Θ // s and photoluminescence quantum yields (PLQYs) of ∼ 90% were achieved. Significantly, TDBA-SBA exhibited excellent TADF properties with a short delayed fluorescence lifetime of only 684 ns and narrow full-width at half-maximum (FWHM) of 44 nm in solution state, accompanied by the high PLQYs of over 80% at high doping concentrations, manifesting the alleviated exciton quenching effects. Consequently, OLEDs based on TDBA-SBA achieved a high maximum external quantum efficiency (EQE) of 29.3% and a maximum brightness of 27663 cd cm −2 . Importantly, an EQE over 20% was realized even at the high brightness of 10000 cd cm −2 , signifying a small efficiency roll-off.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 17
·6908-6917
·
IF 4.569
Xuexia Chen,Ran Pang,Shangwei Wang,Jiangyue Su,Weihong Yuan,Shengjian Jiao,Haiyan Wu,Da Li,Chengyu Li,Hongjie Zhang
Bi3+ has gained increasing attention due to its abundant reserves, adjustable luminous colour and high chemical stability, therefore, Bi3+-activated luminescent materials have already been extensively applied in various fields. Herein, a novel blue-emitting CaNaSb2O6F:Bi3+ (CNSOF:Bi3+) phosphor with a pyrochlore-type structure with the space group Fdm (277) was successfully synthesized. It exhibits a broad absorption band in the n-UV region (290–390 nm) and an ideal blue emission band centered at 441 nm. Interestingly, the wide emission peak of CNSOF:Bi3+ shows strongly temperature-dependent fluorescence properties and good thermal degradation resistance in the cycle temperature range from 298 K to 473 K, and the relative sensitivity is calculated to reach the maximum value of 2.34% K−1 at 423 K. Besides, the phosphor is different from a traditional optical temperature sensing material which shows the emission peak of trivalent rare earth ions. The wide emission peak makes the instrument insensitive to the peak shift, which dramatically reduces the requirement of the instrument, and the emission peak does not shift with the temperature to enhance the measurement stability, thus saving the cost. These results indicate that the CNSOF:Bi3+ blue emitting phosphor has potential applications in temperature sensing.
研究领域:
材料科学
·
无机化学
·
光电子学
·
功能材料
·
传感器技术
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 23
·2001073
·
IF 8.286
Junnan Li,Xuechun Wang,Yeshu Tan,Dong Liang,Yatao Zou,Lei Cai,Tian Wu,Kaichuan Wen,Yusheng Wang,Yajuan Li,Tao Song,Lu Wang,Baoquan Sun
Halide perovskites are promising emitters for light-emitting diodes (LEDs) due to their outstanding optoelectronic properties, i.e., tunable bandgap, high photoluminescence quantum efficiency, and excellent color purity. However, in contrast to their green and red cousins, the present blue perovskite LEDs are still suffering from poor operational lifetime and electroluminescence shift during bias operation, hindering their practical applications in full-color information displays. Developing rational strategies to achieve efficient and stable blue perovskite LEDs is one of the urgent tasks in this community. Herein, through substituting the Pb site with strontium ions, blue perovskite films with stable emission under relatively harsh working conditions, i.e., high electrical bias, constant thermal heating, and UV illumination, are obtained, which accordingly guarantees spectrally stable blue perovskite LEDs with external quantum efficiency of 4.1%. Moreover, different alkaline-earth metal ions are also investigated to further explore the effects of B-site ion substitution on the performance of perovskite LEDs. This work demonstrates an alternative path for the development of spectral-stable blue perovskite LEDs.
研究领域:
材料科学
·
光电技术
·
半导体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）