Co-reporter:Wei Zhang;Xiaohui Qi;Jun Zhao;Lizhong Qin;Tianqing Liu
CrystEngComm (1999-Present) 2017 vol. 19(Issue 35) pp:5214-5222
Publication Date(Web):2017/09/11
DOI:10.1039/C7CE01054K
Ce3+ and Tb3+ co-doped SrAlF5 nanorods were synthesized via a mild hydrothermal method. The XRD results show that the prepared samples are single-phase. FE-SEM reveals the high uniformity of the as-synthesized nanorods (∼1 μm in length and ∼50 nm in diameter). The effect of reaction conditions on the morphology of SrAlF5 was studied. When excited at 254 nm, contrasting weak emission signals of SrAlF5:Tb3+ were observed, while SrAlF5:Ce3+,Tb3+ nanorods exhibited the strong green emission of Tb3+ ions. The energy transfer between Ce3+ and Tb3+ was observed and studied. The mechanism of energy transfer was deduced to be the electric dipole–dipole interaction in the SrAlF5 host. The optimum doping concentration of Ce3+ ions is 7 mol% in SrAlF5:0.01Tb3+. The fluorescence decay curves for Ce3+ and Tb3+ of SrAlF5:Ce3+,Tb3+ nanorods were measured at room temperature. The lifetime of Ce3+ is in the range from 78.6 to 1.2 ns and the lifetime of Tb3+ varies from 4.39 to 7.39 ms. The energy transfer efficiency from Ce3+ to Tb3+ was calculated using lifetime and emission spectra. The chromaticity coordinates of all the samples were calculated and the chromaticity coordinates of SrAlF5:0.06Ce3+,0.01Tb3+ are very near those of the European broadcasting union (EBU) primary green color (0.29, 0.60).
Co-reporter:Ruinian Hua, Xin Zhao, Wei Zhang, Liyan Na, Jun Zhao
Materials Letters 2016 Volume 163() pp:32-35
Publication Date(Web):15 January 2016
DOI:10.1016/j.matlet.2015.10.040
•Eu2+ doped BaSiF6 microrods were synthesized via a simple hydrothermal process.•The strongest line peak position of the samples located at 359 nm precisely.•The optimal doping concentration of Eu2+ ions was confirmed to be about 15 mol%.•The BaSiF6:Eu2+ could be used for sensing, solid-state lasers and spectral calibration materials.Eu2+-doped BaSiF6 microrods with average diameter of 200 nm, and length of 1–4 μm were synthesized via a facile hydrothermal method. The crystal structure and morphology of final products were characterized by X-ray powder diffraction (XRD) and transmission electron microscope (TEM). Upon the excitation of 257 nm UV light, the as-prepared samples exhibit strong and sharp line emission, which originates from the transitions within the 4f7 electron configuration of Eu2+ ions. The optimal doping concentration of Eu2+ ions in BaSiF6 matrix was confirmed to be about 15 mol%.
Co-reporter:Jun Zhao, Ruinian Hua, Wei Zhang, Zhiqing Feng, Dongxin Tang, Liyan Na, Baojiu Chen
Journal of Alloys and Compounds 2014 Volume 588() pp:519-524
Publication Date(Web):5 March 2014
DOI:10.1016/j.jallcom.2013.11.064
•SrAlF5:Yb3+/Er3+ nanorods were synthesized via a microemulsion-hydrothermal process.•Crystal structure and morphology were characterized by using XRD and FESEM.•The upconversion luminescence intensity depend on LD working current was studied.•The post heat-treatment could greatly improve upconversion luminescence.Yb3+ and Er3+ co-doped SrAlF5 nanorods with average diameter of 35 nm and average length of 400 nm were synthesized via a microemulsion-hydrothermal process, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM), respectively. The optimum doping concentration of Yb3+/Er3+ in SrAlF5 matrix was about 4 mol%. The upconversion luminescence intensity dependence on the laser diode (LD) working current was studied and the possible upconversion mechanism was analyzed. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence.Graphical abstractThe SrAlF5 nanorods co-doped with various Yb3+/Er3+ concentrations was synthetized via a microemulsion-hydrothermal process for the first time. It was found that the optimum doping concentration of Yb3+ and Er3+ in SrAlF5 matrix was about 4 mol%. Furthermore, the temperature effect of upconversion luminescence was investigated. It was also found that the post heat-treatment could greatly improve upconversion luminescence.
Co-reporter:Yue Tian, Bining Tian, Baojiu Chen, Cai’e Cui, Ping Huang, Lei Wang, Ruinian Hua
Materials Research Bulletin 2014 53() pp: 38-41
Publication Date(Web):
DOI:10.1016/j.materresbull.2014.01.027
Co-reporter:Yue Tian, Baojiu Chen, Bining Tian, Naisen Yu, Jiashi Sun, Xiangping Li, Jinsu Zhang, Lihong Cheng, Haiyang Zhong, Qingyu Meng, Ruinian Hua
Journal of Colloid and Interface Science 2013 Volume 393() pp:44-52
Publication Date(Web):1 March 2013
DOI:10.1016/j.jcis.2012.10.031
Persimmon-like NaLa(WO4)2 microarchitectures were prepared via hydrothermal process with using trisodium citrate (Na3Cit) as chelated reagent and characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), and fluorescent dynamics. The influences of Na3Cit concentration, organic additivities, and reaction time on the morphologies of NaLa(WO4)2 phosphor were studied. The results revealed that Na3Cit species had double functions of strong ligand and structure-directing reagent that could efficiently control the formation of persimmon-like NaLa(WO4)2 microarchitectures. The possible mechanism for the growth of persimmon-like NaLa(WO4)2 microarchitectures was attributed to the Ostwald ripening mechanism. The energy transfer from Tb3+ to Eu3+ in the persimmon-like NaLa(WO4)2 phosphors was observed. The energy transfer efficiencies and emission colors can be tuned by changing the concentration of Eu3+. Finally, it was deduced that the electric dipole–dipole interaction (D–D) is the main mechanism for energy transfer between Tb3+ and Eu3+ in the persimmon-like NaLa(WO4)2 phosphor.Graphical abstractHighlights► Persimmon-like NaLa(WO4)2 microarchitectures were prepared via hydrothermal process. ► The possible mechanism of persimmon-like NaLa(WO4)2 microarchitectures was proposed. ► Energy transfer between Tb3+ and Eu3+ was confirmed to be electric D–D interaction.
Co-reporter:Wanyue Shao, Ruinian Hua, Wei Zhang, Yue Tian, Jun Zhao, Liyan Na, Jicheng Yu, Zhengang Sun
Powder Technology 2013 Volume 237() pp:326-332
Publication Date(Web):March 2013
DOI:10.1016/j.powtec.2012.12.010
Co-reporter:Yue Tian;Baojiu Chen;Bining Tian;Yuanbing Mao
Journal of Nanoparticle Research 2013 Volume 15( Issue 6) pp:
Publication Date(Web):2013 June
DOI:10.1007/s11051-013-1757-4
Bulk and nanosized GdVO4:Dy3+ phosphors were prepared via a simple co-precipitation process, and their crystal structure, morphology, and spectral properties were studied. It is found that electric dipole–dipole interaction was hindered in the nanosized samples based on the analysis of the dependence of luminescent intensity on the Dy3+ doping concentration. The decay time of the 4F9/2 level in the nanosized GdVO4:2 mol% Dy3+ sample is determined to be longer than that in the 0.3 mol% Dy3+ doped bulk sample. Moreover, the fluorescent lifetime of this level in the nanosized sample is strongly dependent on the index of refraction of the medium surrounding the nanoparticles, and a 0.68 filling factor was obtained. The intrinsic radiative lifetimes and internal quantum efficiencies of the 4F9/2 level of Dy3+ in the nanosized and bulk samples were obtained, which indicate that the internal quantum efficiency of nanosized sample is higher than that of the bulk sample, but the external quantum efficiency is lower.
Co-reporter:Yue Tian, Baojiu Chen, Ruinian Hua, Naisen Yu, Baoquan Liu, Jiashi Sun, Lihong Cheng, Haiyang Zhong, Xiangping Li, Jinsu Zhang, Bining Tian and Hua Zhong
CrystEngComm 2012 vol. 14(Issue 5) pp:1760-1769
Publication Date(Web):05 Jan 2012
DOI:10.1039/C1CE06232H
Three dimensional (3D) flower-shaped microarchitectures of NaY(WO4)2 were synthesized via a microwave-assisted hydrothermal process in the presence of trisodium citrate (Na3Cit) and a post-calcination process. The effects of reaction conditions on the morphology of precursor microstructures were studied. It was found that Na3Cit, as the chelating agent and shape modifier, plays a key role in the microstructure growth. A possible growth mechanism for the flower-shaped microarchitectures was proposed. The as-formed precursor can completely transform into NaY(WO4)2 with its original flower-shaped morphology via a heat treatment process. The concentration and temperature quenching behaviors of Eu3+ fluorescence in the flower-shaped NaY(WO4)2 were studied, and the optimal doping concentration was confirmed, meanwhile the activation energy was obtained. Judd-Ofelt parameters Ωλ (λ = 2, 4 and 6) of Eu3+ in the flower-shaped NaY(WO4)2 phosphor were obtained by using the emission spectrum of Eu3+, moreover the radiative transition properties were analyzed.
Co-reporter:Bining Tian, Baojiu Chen, Yue Tian, Jiashi Sun, Xiangping Li, Jinsu Zhang, Haiyang Zhong, Lihong Cheng, Zhongli Wu, Ruinian Hua
Ceramics International 2012 Volume 38(Issue 5) pp:3537-3540
Publication Date(Web):July 2012
DOI:10.1016/j.ceramint.2011.12.068
Abstract
Eu3+ doped BaGd2ZnO5 phosphor was synthesized by a traditional solid-state reaction. The crystal structure of the product was characterized by means of X-ray diffraction (XRD). The ultraviolet (UV) and vacuum ultraviolet (VUV) photoluminescence properties of the phosphor were studied. Excitation spectra inferred that efficient energy transfer from Gd3+ to Eu3+ exists in the BaGd2ZnO5:Eu3+. The visible quantum cutting process based on the Gd3+–Eu3+ couple was observed in the BaGd2ZnO5:Eu3+ phosphor. Two-step energy transfer process from Gd3+ to Eu3+, viz. a cross-relaxation and a sequential transfer of the remaining excitation energy, is the mechanism responsible for visible quantum cutting in BaGd2ZnO5:Eu3+ phosphor. Quantum cutting efficiency in BaGd2ZnO5:Eu3+ was calculated to be around 133%.
Co-reporter:Bining Tian, Baojiu Chen, Yue Tian, Jiashi Sun, Xiangping Li, Jinsu Zhang, Haiyang Zhong, Lihong Cheng, Ruinian Hua
Journal of Physics and Chemistry of Solids 2012 Volume 73(Issue 11) pp:1314-1319
Publication Date(Web):November 2012
DOI:10.1016/j.jpcs.2012.06.016
BaGd2ZnO5:Dy3+ phosphors were synthesized by a traditional solid-state reaction. The crystal structure of the phosphors was characterized by X-ray diffraction (XRD). The blue emission (456 nm) corresponding to 4H15/2→6H15/2 transition was observed at higher sample temperatures, and the population mechanism of 4H15/2 level was assigned to the thermal excitation of 4F9/2 level. The fluorescence concentration quenching of 4F9/2 level was studied based on Van Uitert's model, and that the electric dipole–dipole interaction was confirmed to be the responsible mechanism for the energy transfer between Dy3+ ions. Finally, the fluorescence thermal quenching of 4F9/2 level was studied, and the crossover effect was found to be the main physical mechanism for the fluorescence temperature quenching of Dy3+.Highlights► BaGd2ZnO5:Dy3+ phosphors were synthesized by a traditional solid-state reaction. ► Energy transfer between Dy3+ ions was confirmed to be electric dipole–dipole interaction. ► The thermal excitation luminescence of 4I15/2 level was observed. ► Crossover effect is the main mechanism for fluorescence temperature quenching of Dy3+.
Co-reporter:Yue Tian, Ruinian Hua, Jicheng Yu, Jiashi Sun, Baojiu Chen
Materials Chemistry and Physics 2012 Volume 133(2–3) pp:617-620
Publication Date(Web):16 April 2012
DOI:10.1016/j.matchemphys.2012.01.025
Yb3+/Er3+ co-doped Gd6WO12 nanoparticles were prepared via a coprecipitation technique and characterized by means of XRD and FE-SEM. The effect of excitation power density in different regions on the upconversion mechanisms was investigated. It was found that the green upconversion emissions is a two photons process when the excitation power density is low, but a three photons process occurs when the excitation power density is high. However, the red upconversion emission is still a two photons process. A possible mechanism for three photons green upconversion luminescence was proposed and discussed.Highlights► Yb3+/Er3+ doped Gd6WO12 nanoparticles were prepared ► The effect of power on upconversion in Gd6WO12 nanoparticles was found ► A possible mechanism for three photons green upconversion was proposed
Co-reporter:Yue Tian, Baojiu Chen, Xiangping Li, Jinsu Zhang, Bining Tian, Jiashi Sun, Lihong Cheng, Haiyang Zhong, Hua Zhong, Ruinian Hua
Journal of Solid State Chemistry 2012 Volume 196() pp:187-196
Publication Date(Web):December 2012
DOI:10.1016/j.jssc.2012.06.004
Tb3+, Eu3+ codoped YF3 nano- and micro-crystals with the morphologies of ellipsoid-like nanoplate, spindle, sandwich-structural rhombus and nanoaggregate were synthesized through a solvothermal method. The morphologies of the prepared products can be tailored by controlling the volume ratio of ethylene glycol (EG) to H2O, solvent type or the reaction time. A possible formation mechanism of the sandwich-structural rhombus like YF3 phosphor was proposed. The emitting colors of YF3:Tb3+,Eu3+ phosphors can be easily tuned from yellowish green, yellow to orange by increasing Eu3+ concentration. The energy transfer from Tb3+ to Eu3+ in YF3 phosphors was studied. It was found that the interaction type between Tb3+ and Eu3+ is electric dipole–dipole interaction.Graphical abstractSandwich-structural rhombus like YF3:Tb3+, Eu3+ phosphors were synthesized through a solvothermal process. The formation mechanism of the sandwich-structural rhombus like YF3:Tb3+, Eu3+ phosphors was studied.Highlights► YF3 nano- and micro-crystals were synthesized through solvothermal route. ► A formation mechanism of the sandwich-structural rhombus like YF3 was proposed. ► The emitting colors of YF3:Tb3+,Eu3+ phosphors can be tuned. ► Energy transfer from Tb3+ to Eu3+ is confirmed as electric dipole–dipole interaction.
Co-reporter:Yue Tian, Ruinian Hua, Naisen Yu, Wei Zhang, Liyan Na, Baojiu Chen
Journal of Alloys and Compounds 2011 Volume 509(Issue 41) pp:9924-9929
Publication Date(Web):13 October 2011
DOI:10.1016/j.jallcom.2011.07.095
Hexagonal phase NaYF4 microtubes co-doped with Yb3+ and Er3+ were synthesized through a hydrothermal process with YF3 submicrospindles as precursor. The X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) were utilized to characterize the structure and morphology of the as-prepared products. XRD results show that pure cubic NaYF4 crystals can be obtained when reaction time is 2 h. While the product is mixture of cubic and hexagonal phase NaYF4 when reaction time is from 7 to 20 h. Continuing to increase the reaction time to 24 h, the pure hexagonal NaYF4 crystals were formed. The FE-SEM and TEM results show that the morphology of pure cubic NaYF4 is spherical clusters composed of spherical nanoparticles with average diameter of about 100 nm and the pure hexagonal NaYF4 crystals have tubular structure with out diameter of about 0.3–0.5 μm, inner diameter of about 0.5–1 μm and length ranging from 3 to 12 μm. The luminescence properties of Yb3+/Er3+ co-doped cubic and hexagonal phase NaYF4 microcrystals were also studied. Under 980-nm excitation, the upconversion luminescence (UCL) intensity of hexagonal phase NaYF4 microtubes is much stronger than that of cubic phase clusters. Moreover, both red and green upconversion are ascribed to the two-photon process. Therefore, hexagonal phase NaYF4 microtubes with high UCL efficiency may have a potential application in photonic device.Highlights► Yb3+/Er3+ co-doped NaYF4 microtubes were prepared through a hydrothermal process with YF3 submicrospindles as precursor. ► Hydrothermal treatment time plays an important role in the control of phase and morphology of the product. ► The UCL efficiency of Yb3+/Er3+co-doped NaYF4 microtubes is much higher than that of cubic phase Yb3+/Er3+ co-doped NaYF4 clusters. ► Yb3+/Er3+ co-doped NaYF4 microtubes may have a potential application in photonic device.
Co-reporter:Yue Tian, Baojiu Chen, Bining Tian, Ruinian Hua, Jiashi Sun, Lihong Cheng, Haiyang Zhong, Xiangping Li, Jinsu Zhang, Yanfeng Zheng, Tingting Yu, Libo Huang, Qingyu Meng
Journal of Alloys and Compounds 2011 Volume 509(Issue 20) pp:6096-6101
Publication Date(Web):19 May 2011
DOI:10.1016/j.jallcom.2011.03.034
Flower-like Y2(MoO4)3:Dy3+ phosphors have been synthesized via a co-precipitation approach with the aid of β-cyclodextrin. The crystal structure and morphology of the phosphors were characterized by XRD (X-ray diffraction) and FE-SEM (field emission scanning electron microscopy), respectively. The excitation and emission properties of the phosphors were examined by fluorescence spectroscopy. The dependence of color coordinates on the Dy3+ doping concentration was analyzed. The energy transfer mechanism between Dy3+ ions was studied based on the Huang's theory, I-H and Van Uitert's models. It was concluded simultaneously from these three routes that the electric dipole–dipole interaction between Dy3+ ions is the main physical mechanism for the energy transfers between Dy3+.Highlights► Flower-shaped Y2(MoO4)3 phosphors were prepared by a co-precipitation method. ► The structure and morphology of the prepared phosphors were characterized. ► Energy transfer between Dy3+ was studied by Huang's theory, IH and Uitert's models.
Co-reporter:Yue Tian;Jicheng Yu;Baojiu Chen;Jiashi Sun;Lihong Cheng
Chinese Journal of Chemistry 2010 Volume 28( Issue 6) pp:921-927
Publication Date(Web):
DOI:10.1002/cjoc.201090172
Abstract
A new method for silica-coated CaF2:Eu3+ core-shell nanoparticles functionalized with oxalic acid for bio-conjugation to bovine serum albumin (BSA) proteins has been developed. Moreover, CaF2:Eu3+/SiO2 core-shell nanoparticles modified with oxalic acid are biocompatible and can be dispersed in water. As an organic functional molecule, oxalic acid is able to react with hydroxyl groups existed on the surface of SiO2 layer by esterification reaction to form carboxylic acid for further bio-conjugation with BSA. The final products were characterized by means of X-ray diffraction (XRD), transmission electron microscope (TEM), field-emission scanning electron microscopy (FE-SEM), ultraviolet (UV) spectrophotometer, infrared (IR) spectrophotometer and photoluminescence (PL) spectra. XRD result confirmed the phase purity of CaF2:10 mol% Eu3+ and CaF2:10 mol% Eu3+/SiO2 nanoparticles obtained from the quaternary reverse micelles of cetyltrimethylammonium bromide (CTAB), cyclohexane, n-pentanol and water. Images of TEM and FE-SEM showed that the average grain sizes of CaF2:10 mol% Eu3+/SiO2 and bio-conjugation of CaF2:10 mol% Eu3+/SiO2 nanoparticles with BSA were about 17 nm. The patterns of UV and IR spectra showed that BSA was linked to CaF2:10 mol% Eu3+/SiO2 nanoparticles. In the emission spectrum of CaF2:10 mol% Eu3+/SiO2 conjugated by BSA nanoparticles, characteristic emission peaks of Eu3+ within the wavelength ranging from 500 to 700 nm were observed, which is corresponding to the transitions from the excited 5D0 levels to 7FJ levels. This confirmed that the Eu3+ dopant ion is located in a Ca2+ crystal site with Tdsymmetry. CaF2:10 mol% Eu3+/SiO2 conjugated by BSA nanoparticles remain stable in aqueous media within 15 d with pH ranging from 2 to 9. Therefore, these luminescent colloidal nanoparticles can be potentially employed as targeted fluorescent labels in biomedical research applications.
Co-reporter:Yue Tian;Ji-Cheng Yu;Xiao-Hui Qi
Journal of Materials Science: Materials in Electronics 2009 Volume 20( Issue 5) pp:
Publication Date(Web):2009 May
DOI:10.1007/s10854-008-9748-4
CaF2:Eu nanoparticles capped with chitosan and bio-conjugation of CaF2:Eu/chitosan nanoparticles with bovine serum albumin (BSA) were synthesized via microemulsion method. As a surfactant, chitosan was employed to cap the nanoparticles during the synthesis process and provided functional groups, such as amino group for further bio-conjunction with BSA. CaF2:Eu and CaF2:Eu/chitosan–BSA nanoparticles were characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), ultraviolet spectrophotometer (UV), infrared spectrophotometer (IR) and photoluminescence spectrophotometer (PL). The XRD results indicated that the CaF2:Eu and CaF2:Eu/chitosan-BSA nanoparticles have crystallized well and the average sizes were about 16 and 19 nm, respectively. Images of FE-SEM showed that the average grain sizes of the CaF2:Eu and bio-conjunction of CaF2:Eu/chitosan nanoparticles with BSA were about 19 and 20 nm. The patterns of UV spectra and IR spectra showed that BSA was linked to CaF2:Eu/chitosan nanoparticles. In the emission spectrum of the CaF2:Eu/chitosan–BSA nanoparticles, characteristic emission peaks of Eu3+ within the wavelength ranging from 500 to 700 nm were observed, corresponding to the transitions from the excited 5D0 levels to 7FJ levels. This confirmed that the Eu3+dopant ion is located in a Ca2+ crystal site with Td symmetry.
Co-reporter:Yue Tian, Xiaohui Qi, Xiaowei Wu, Ruinian Hua and Baojiu Chen
The Journal of Physical Chemistry C 2009 Volume 113(Issue 24) pp:10767-10772
Publication Date(Web):May 27, 2009
DOI:10.1021/jp901053q
Novel Y2(MoO4)3:Eu3+ red phosphors were synthesized through a simple coprecipitation process and characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and fluorescent spectrophotometry. The results of XRD and FE-SEM show that resultant samples are single phase and have flowerlike shape. In the excitation spectra of Y2(MoO4)3:Eu3+ phosphors, by monitoring 616 nm, the charge transfer bands (CTB) of Eu3+→O2- and Mo6+→O2- centering at around 264 and 310 nm can be observed, respectively. Moreover, the intensity ratio of charge transfer band between Eu3+→O2- and Mo6+→O2- increases with increasing Eu3+ ions doping concentration. The characteristic red emission at around 616 nm of Eu3+ ions is also observed, ascribed to the 5D0→7F2 transition of Eu3+ ions, and the optimal doping concentration is 12 mol %. Finally, the Ωλ (λ = 2 and 4) intensity parameters and Huang−Rhys factor were also calculated according to Judd−Ofelt theory and multiphonon relaxation theory, respectively.
Co-reporter:Rui-Nian HUA;Jing-Hua NIU;Tian-Zhi YU;Zi-Ruo HONG;Wen-Lian LI;Sheng-Di FAN
Chinese Journal of Chemistry 2008 Volume 26( Issue 4) pp:755-758
Publication Date(Web):
DOI:10.1002/cjoc.200890141
Abstract
Tris-(8-quinolinolato) aluminum (AlQ3) organic nanoparticles with an average diameter 20 nm were prepared through a reprecipitation method. The AlQ3 nanoparticles are spherical and the average particle size does not change by varying the aging time. The photoluminescent and electroluminescent properties were investigated via the AlQ3 nanoparticles and the device based on the AlQ3 nanoparticles, respectively. Blue shift of both the photoluminescence and electroluminescence spectra for the AlQ3 nanoparticles was observed. With increasing the driving bias, the maximum EL emission peak of the AlQ3 nanoparticles was shifted to longer wavelength. The maximum luminance and luminous efficiency of the AlQ3 nanoparticle-based device are about 600 cd/m2 at driving bias 16V and 0.19 cd/A at a current density of 150 mA/cm2, respectively. The obvious quantum size effect of electro-luminescence devices with the AlQ3 nanoparticles has been proved, which will open a useful route and new studying field of organic electronic devices, and the study of the fundamental process connecting both of those more conventional classes of materials, i.e., organic molecular crystals.
Co-reporter:Ruinian Hua, Jicheng Yu, Huiming Jiang, Chunshan Shi
Journal of Alloys and Compounds 2007 Volume 432(1–2) pp:253-257
Publication Date(Web):25 April 2007
DOI:10.1016/j.jallcom.2006.05.108
The complex fluorides KMF3:Re (M = Mg, Zn; Re = Eu, Ce) were solvothermally synthesized at 180 °C and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectroscopy (IR) and spectrofluorometer. In the emission spectrum of KMgF3:Eu powders, there is one sharp line emission located at 360 nm, which is arisen from f→f (6P7/2→8S7/2) transition of Eu2+ in KMgF3 lattice. The excitation spectrum of KMgF3:Eu powders monitored at 360 nm emission has only one broad peak maximum at about 250 nm. In the emission spectrum of KZnF3:Eu, there is one sharp line emission located at 360 nm (6P7/2→8S7/2 transition of Eu2+) and one broad range of 370–550 nm with a maximum center located at 461 nm, which is arisen from d→f (4f65d→8S7/2) transition of Eu2+. The excitation spectrum of KZnF3:Eu monitored at 360 nm emission has one broad peak maximum at about 253 nm. The typical doublet 5d–4f emission peaks of Ce3+ in KZnF3 powders are shown.
Co-reporter:Ruinian Hua, Jinghua Niu, Mingtao Li, Tianzhi Yu, Wenlian Li
Chemical Physics Letters 2006 Volume 419(1–3) pp:269-272
Publication Date(Web):15 February 2006
DOI:10.1016/j.cplett.2005.11.092
Abstract
ZnS:Tb/CdS core/shell nanocrystals (NCs) were synthesized by reverse micelle method, and with a core crystal diameter of 3.0 and a 0.5 nm thick CdS shell and used as an electroluminescent material. Electroluminescent (EL) devices having a hybrid organic/inorganic multilayer structure were fabricated. Electron–hole recombination was confined at the ZnS:Tb/CdS NCs layer. Three emissions peaked at 440 nm form ZnS host, 546 nm (5D4–7F5) and 577 nm (5D4–7F4) of Tb3+ center were observed when the hybrid EL device at a bias of 13 V. The maximum luminance of the ZnS:Tb/CdS NCs-based reached 19 cd/m2 at 25 V.
