The comparative study of epitaxial 380-run-thick p-Al0.091 Ga0.909 N materials without and with special surface chemical treatment is systematically carried out. After the treatment process, the deep level luminous pe...The comparative study of epitaxial 380-run-thick p-Al0.091 Ga0.909 N materials without and with special surface chemical treatment is systematically carried out. After the treatment process, the deep level luminous peak in the 10 K photoluminescence spectrum is eliminated due to the decrease of surface nitrogen vacancy VN related defective sites, while the surface root-mean-square roughness in atomic force microscopy measurement is decreased from 0.395nm to 0.229nm by such a surface preparation method. Furthermore, the performance of surface contact with Ni/Au bilayer metal fihns is obviously improved with the reduction of the Schottky barrier height of 55meV. The x-ray photoelectron spectroscopy （XPS） results show a notable surface element content change after the treatment which is considered to be the cause of the above-mentioned surface characteristics improvement.展开更多
The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanos...The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanostructure are fabricated toward achieving efficient upconversion for 808 nm excitation, which have great potential for optical applications, especially photobiological applications.展开更多
Monovalent ions Li＋, Na＋, and K＋, as charge compensators, are introduced into CaYA1307： M （M = Eu3＋, Ce~＋） in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions d...Monovalent ions Li＋, Na＋, and K＋, as charge compensators, are introduced into CaYA1307： M （M = Eu3＋, Ce~＋） in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYA1307 are investigated. In addition, the influence of charge compensation ion Li＋ which has a more obvious role in improving luminescence intensity on CaYA1307： Eu3＋ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3＋ is achieved by adding alkali metal ion Li＋ under 393-nm excitation.展开更多
Lanthanum-doped double halide perovskite has attracted increasing interest due to its distinctive upconversion and near-infrared(NIR) luminous characteristics.Here,erbium ion(Er^(3+)) doped Cs_(2)(Na/Ag)BiCl_(6) micro...Lanthanum-doped double halide perovskite has attracted increasing interest due to its distinctive upconversion and near-infrared(NIR) luminous characteristics.Here,erbium ion(Er^(3+)) doped Cs_(2)(Na/Ag)BiCl_(6) microcrystals(MCs) were synthesized and proved to be one of the most prospective candidates for optical thermometry.The enhancement of both white light from self-trapped exciton emission and NIR emission from Er^(3+) ion of Cs_(2)AgBiCl_(6) microcrystals is caused by lattice distortion due to Na^(+) ion doping.Fluorescence intensity ratio and lifetime methods provide self-referenced and sensitive thermometry under 405 and/or 980 nm laser excitation at the temperatures from 80 to 480 K.Besides,the maximum values of relative and absolute sensitivity of 3.62%/K and 27//K can be achieved in the low to high temperature range under 980 and 405 nm laser co-excitation.Through the experimental analysis,Er^(3+)doped Cs_(2)(Na/Ag)BiCl_(6) double perovskite is considered to be an ideal self-calibrating thermometric material due to its good long-term stability and multi-mode function of excitation and detection.展开更多
Accurate and dynamic visualization of vascular diseases can contribute to restraining further deterioration from diseases in a timely manner.However,visualization is still unable to precisely determine whether and to ...Accurate and dynamic visualization of vascular diseases can contribute to restraining further deterioration from diseases in a timely manner.However,visualization is still unable to precisely determine whether and to what extent blood vessels or brain tissues are damaged.Here,we report novel benzobis(1,2,5-thiadiazole)-based second near-infrared region(NIR-II)fluorophores HY1-HY4 with highly twisted structures(55°at the S_(0) state),extremely strong aggregation-induced emission(AIE)characteristics(I/I_(0)>13),and remarkably high fluorescence quantum yields(QYs)(up to 14.45%)in the NIR-II region(>1000 nm)and∼0.27%in the nearinfrared IIb window(NIR-IIb,>1500 nm)in aqueous solution.Using NIR-IIb AIE HY4 dots,high-resolution NIR-IIb fluorescence imaging of revascularization and thrombolysis,and real-time feedback of the therapeutic efficacy of Chinese medicine Dengzhan Xixin injection(DXI)on ischemic stroke,were achieved for the first time.In addition,results showed that DXI conferred neuroprotection against cerebral ischemia injury mediated via the angiogenesis pathway.These attractive results provide a new perspective for designing ultrabright NIR-IIb probes for vascular-related phenomena,disease assessment,and precise intraoperative imageguided therapy with a deeper tissue penetration depth and higher resolution.展开更多
We fabricate white phosphorescent organic light-emitting diodes （PHOLEDs） with three dopants and double emissive layer （EML） to achieve color stability. The white PHOLEDs use FIrpic dopant for blue EML （B- EML）,...We fabricate white phosphorescent organic light-emitting diodes （PHOLEDs） with three dopants and double emissive layer （EML） to achieve color stability. The white PHOLEDs use FIrpic dopant for blue EML （B- EML）, and Ir（ppy）3：Ir（piq）3 dopants for green：red EML （GR-EML） with N,N＇-dicarbazolyl-3, 5-benzene （mCP） as host material. Thicknesses of B-EML and GR-EML are adjusted to form a narrow recombination zone at two EML＇s interface and charge trapping happens in EML according to wide highest occupied molecular orbital and/or lowest unoccupied molecular orbital energy band gap of mCP and smaller energy band gap of dopants. The total thickness of both EMLs is fixed at 30 nm in the device structure of ITO （150 nm）/MoO3 （2 nm）/N,N＇-diphenyl-N,N＇-bis（1-naphthyl-phenyl）-（1,1″-biphenyl）-4, 4＇-diamine （70 nm）/ meP：Firpic-8.0% （12 nm）/mCP：Ir（ppy）3-3.0%：Ir（piq）3-1.5% （18 nm）/2″,2＇,2＂＇-（1,3,5-benzinetriyl）-tris（1- phenyl-l-H-benzimidazole） （30 nm）/8-hydroxyquinolinolato-lithium （2 nm）/A1 （120 nm）. White PHOLED shows 18.25 cd/A of luminous efficiency and white color coordinates of （0.358 and 0.378） at 5000 cd/m2 and color stability with slight CIExy change of （0.028 and 0.002） as increasing luminance from 1000 to 5000 cd/m^2.展开更多
基金Supported by the National Key Basic Research Special Foundation of China under Grant No T（32000036601, the National High Technology Program of China under Grant Nos 2001AA313130 and 2004AA31G060, the National Natural Science Foundation of China under Crant Nos 60244001 and 60390074, and the Beijing Science and Teclnology Plan （D04040040321）.
文摘The comparative study of epitaxial 380-run-thick p-Al0.091 Ga0.909 N materials without and with special surface chemical treatment is systematically carried out. After the treatment process, the deep level luminous peak in the 10 K photoluminescence spectrum is eliminated due to the decrease of surface nitrogen vacancy VN related defective sites, while the surface root-mean-square roughness in atomic force microscopy measurement is decreased from 0.395nm to 0.229nm by such a surface preparation method. Furthermore, the performance of surface contact with Ni/Au bilayer metal fihns is obviously improved with the reduction of the Schottky barrier height of 55meV. The x-ray photoelectron spectroscopy （XPS） results show a notable surface element content change after the treatment which is considered to be the cause of the above-mentioned surface characteristics improvement.
基金financially supported in part by National Key R&D Program of China (Nos.2020YFA0406103,2017YFA0207301),NSFC (Nos.21725102,91961106,U1832156,22075267)Science and Technological Fund of Anhui Province for Outstanding Youth (No.2008085J05)+3 种基金Youth Innovation Promotion Association of CAS (No.2019444)Young Elite Scientist Sponsorship Program by CAST,China Postdoctoral Science Foundation (Nos.BH2340000099,BH2340000138)Users with Excellence Program of Hefei Science Center CAS (No.2020HSC-UE003)support from USTC Center for Micro- and Nanoscale Research and Fabrication。
文摘The construction of core-shell structure is an effective strategy for promoting the emission efficiency of upconversion nanocrystals(UCNCs). In this work, the UCNCs based on Nd-doping with a multilayer coreshell nanostructure are fabricated toward achieving efficient upconversion for 808 nm excitation, which have great potential for optical applications, especially photobiological applications.
基金supported by the National Natural Science Foundation of China(Nos.11204113,61265004,and 51272097)the Foundation of Application Research of Yunnan Province(No.2011FB022)+2 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education(No.20115314120001)the Postdoctoral Science Foundation of China(No.2011M501424)the Nature and Science Fund from Yunnan ProvinceMinistry of Education(No.2011C13211708)
文摘Monovalent ions Li＋, Na＋, and K＋, as charge compensators, are introduced into CaYA1307： M （M = Eu3＋, Ce~＋） in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYA1307 are investigated. In addition, the influence of charge compensation ion Li＋ which has a more obvious role in improving luminescence intensity on CaYA1307： Eu3＋ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3＋ is achieved by adding alkali metal ion Li＋ under 393-nm excitation.
基金Project supported by the Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and SystemsBasic Research Project for Outstanding Young Teachers of Heilongjiang Province (YQJH2023128)Cultivation Project of Double First-class Initiative Discipline by Heilongjiang Province(LJGXCG2022-061)。
文摘Lanthanum-doped double halide perovskite has attracted increasing interest due to its distinctive upconversion and near-infrared(NIR) luminous characteristics.Here,erbium ion(Er^(3+)) doped Cs_(2)(Na/Ag)BiCl_(6) microcrystals(MCs) were synthesized and proved to be one of the most prospective candidates for optical thermometry.The enhancement of both white light from self-trapped exciton emission and NIR emission from Er^(3+) ion of Cs_(2)AgBiCl_(6) microcrystals is caused by lattice distortion due to Na^(+) ion doping.Fluorescence intensity ratio and lifetime methods provide self-referenced and sensitive thermometry under 405 and/or 980 nm laser excitation at the temperatures from 80 to 480 K.Besides,the maximum values of relative and absolute sensitivity of 3.62%/K and 27//K can be achieved in the low to high temperature range under 980 and 405 nm laser co-excitation.Through the experimental analysis,Er^(3+)doped Cs_(2)(Na/Ag)BiCl_(6) double perovskite is considered to be an ideal self-calibrating thermometric material due to its good long-term stability and multi-mode function of excitation and detection.
基金This work was partially supported by grants from the National Key R&D Program of China(no.2020YFA09-08800)NSFC(nos.81773674,81573383,21763002,82111530209,and 91959103)+5 种基金Shenzhen Science and Technology Research Grant(no.JCYJ20190808152019182)Hubei Province Scientific and Technical Innovation Key Project(no.2020BAB058),the Applied Basic Research Program of Wuhan Municipal Bureau of Science and Technology(no.2019020701011429)the Major Science and Technology Project of Sichuan Science and Technology Department(no.2019YFSY0046)Project First-Class Disciplines Development Supported by Chengdu University of Traditional Chinese Medicine(no.CZYJC1903)Tibet Autonomous Region Science and Technology Plan Project Key Project(no.XZ201901-GB-11)the Local Development Funds of Science andTechnology Department of Tibet(nos.XZ202102YD0033C and XZ202001YD0028C),and the Fundamental Research Funds for the Central Universities.
文摘Accurate and dynamic visualization of vascular diseases can contribute to restraining further deterioration from diseases in a timely manner.However,visualization is still unable to precisely determine whether and to what extent blood vessels or brain tissues are damaged.Here,we report novel benzobis(1,2,5-thiadiazole)-based second near-infrared region(NIR-II)fluorophores HY1-HY4 with highly twisted structures(55°at the S_(0) state),extremely strong aggregation-induced emission(AIE)characteristics(I/I_(0)>13),and remarkably high fluorescence quantum yields(QYs)(up to 14.45%)in the NIR-II region(>1000 nm)and∼0.27%in the nearinfrared IIb window(NIR-IIb,>1500 nm)in aqueous solution.Using NIR-IIb AIE HY4 dots,high-resolution NIR-IIb fluorescence imaging of revascularization and thrombolysis,and real-time feedback of the therapeutic efficacy of Chinese medicine Dengzhan Xixin injection(DXI)on ischemic stroke,were achieved for the first time.In addition,results showed that DXI conferred neuroprotection against cerebral ischemia injury mediated via the angiogenesis pathway.These attractive results provide a new perspective for designing ultrabright NIR-IIb probes for vascular-related phenomena,disease assessment,and precise intraoperative imageguided therapy with a deeper tissue penetration depth and higher resolution.
文摘We fabricate white phosphorescent organic light-emitting diodes （PHOLEDs） with three dopants and double emissive layer （EML） to achieve color stability. The white PHOLEDs use FIrpic dopant for blue EML （B- EML）, and Ir（ppy）3：Ir（piq）3 dopants for green：red EML （GR-EML） with N,N＇-dicarbazolyl-3, 5-benzene （mCP） as host material. Thicknesses of B-EML and GR-EML are adjusted to form a narrow recombination zone at two EML＇s interface and charge trapping happens in EML according to wide highest occupied molecular orbital and/or lowest unoccupied molecular orbital energy band gap of mCP and smaller energy band gap of dopants. The total thickness of both EMLs is fixed at 30 nm in the device structure of ITO （150 nm）/MoO3 （2 nm）/N,N＇-diphenyl-N,N＇-bis（1-naphthyl-phenyl）-（1,1″-biphenyl）-4, 4＇-diamine （70 nm）/ meP：Firpic-8.0% （12 nm）/mCP：Ir（ppy）3-3.0%：Ir（piq）3-1.5% （18 nm）/2″,2＇,2＂＇-（1,3,5-benzinetriyl）-tris（1- phenyl-l-H-benzimidazole） （30 nm）/8-hydroxyquinolinolato-lithium （2 nm）/A1 （120 nm）. White PHOLED shows 18.25 cd/A of luminous efficiency and white color coordinates of （0.358 and 0.378） at 5000 cd/m2 and color stability with slight CIExy change of （0.028 and 0.002） as increasing luminance from 1000 to 5000 cd/m^2.
