Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed...Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed on fiber surface because of fiber silanization.The sizes and tip sharpness of the nano-urchins could be controlled by Ag seeds.The elements distribution analysis indicated there was high Ag content in tip-top for better surface enhance Raman scattering performance.The detectable concentration could be as low as 10-8 M using crystal violet molecules as analyte.Moreover,the fiber probes were stable in air,due to Au in the alloy.This fiber probe could be used for low content single molecular analysis.展开更多
Nd^(3+),Er^(3+)ions doped 0.9(Ge_(0.25)Ga_(0.10)S_(0.65))-0.1CsBr chalcohalide glass were prepared via melt-quenching method,and heat treated at 360℃ in high purity Ar gas atmosphere for different hours for the early...Nd^(3+),Er^(3+)ions doped 0.9(Ge_(0.25)Ga_(0.10)S_(0.65))-0.1CsBr chalcohalide glass were prepared via melt-quenching method,and heat treated at 360℃ in high purity Ar gas atmosphere for different hours for the early stage of crystallization.The effect of heat treatment durations on visible upconversion luminescence and near infrared emission from Nd^(3+)ions and Er^(3+)ions were investigated.The specimens kept amorphous status until the heat treatment duration extended to 10 hours,for Ga_(2)S_(3) nano-crystal formation in glass matrix.The stark splitting in visible upconversion luminescence center at 600 nm from Nd^(3+)ions weakened,and disappeared,and the shape of infrared emission centered at 1550 nm from Er^(3+)ions changed,with the heat treatment duration increased.The lifetime of Nd^(3+):^(4)F_(3/2) level and Er^(3+):^(4)I_(13/2) level dropped,then increased with heat treatment duration increased.X-ray diffraction patterns and transmission electron microscope images confirmed the amorphous state and Ga_(2)S_(3) nano-crystals formation in glass matrix.The rare earth ions local environment changes with heat treatment duration were proposed,based on the emission and lifetime changes.This research will be helpful for the understanding of rare earth doped chalcohalide crystallization mechanism and processes.展开更多
Ultra-small PbSe quantum dots (QDs) were synthesized using conventional hot-injection method.A small amount of Sn was used as a nucleation promotion agent to control nucleation and growth during the QDs synthesis proc...Ultra-small PbSe quantum dots (QDs) were synthesized using conventional hot-injection method.A small amount of Sn was used as a nucleation promotion agent to control nucleation and growth during the QDs synthesis process.The average diameter of the QDs is about 1.6 nm,of which absorption peak centers at 550 nm and photoluminescence peak centers at 750 nm under 350 nm laser excitation with power as low as 500 μW.Transmission electron microscopy images confirm that the QDs size well matches with the calculated diameter from Brus equation.This match and electron energy loss spectroscopy analysis proves that Sn is not involved into the final structure of the ultra-small PbSe QDs.An ion-exchange process was proposed for the nucleation control and ultra-small QDs synthesis.The prepared ultra-small QDs could be a promising candidate for luminescence,solar cell devices,and others.展开更多
基金Funded by the Project of Sanya Yazhou Bay Science and Technology City (No.SCKJ-JYRC-2022-44)the Opening Funding of the State Key Laboratory of Silicate Materials for Architecture (SySJJ2018-06)+1 种基金the Fundamental Research Funds for the Central Universities (WUT:2016VA096),Chinathe Research Program (No.S2634339)through a Grant Provided by the Ministry of SMEs and Startups。
文摘Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed on fiber surface because of fiber silanization.The sizes and tip sharpness of the nano-urchins could be controlled by Ag seeds.The elements distribution analysis indicated there was high Ag content in tip-top for better surface enhance Raman scattering performance.The detectable concentration could be as low as 10-8 M using crystal violet molecules as analyte.Moreover,the fiber probes were stable in air,due to Au in the alloy.This fiber probe could be used for low content single molecular analysis.
基金Funded by the Opening Funding of the State Key Laboratory of Silicate Materials for Architecture(SYSJJ2018-06)the Fundamental Research Funds for the Central Universities(WUT:2016IVA096)China+1 种基金the Research Program(No.S2634339)through a Grant Provided by the Ministry of SMEs and Startupsthe Research on Advanced Optical Science and Technology through a Grant Funded by the GIST,Korea。
文摘Nd^(3+),Er^(3+)ions doped 0.9(Ge_(0.25)Ga_(0.10)S_(0.65))-0.1CsBr chalcohalide glass were prepared via melt-quenching method,and heat treated at 360℃ in high purity Ar gas atmosphere for different hours for the early stage of crystallization.The effect of heat treatment durations on visible upconversion luminescence and near infrared emission from Nd^(3+)ions and Er^(3+)ions were investigated.The specimens kept amorphous status until the heat treatment duration extended to 10 hours,for Ga_(2)S_(3) nano-crystal formation in glass matrix.The stark splitting in visible upconversion luminescence center at 600 nm from Nd^(3+)ions weakened,and disappeared,and the shape of infrared emission centered at 1550 nm from Er^(3+)ions changed,with the heat treatment duration increased.The lifetime of Nd^(3+):^(4)F_(3/2) level and Er^(3+):^(4)I_(13/2) level dropped,then increased with heat treatment duration increased.X-ray diffraction patterns and transmission electron microscope images confirmed the amorphous state and Ga_(2)S_(3) nano-crystals formation in glass matrix.The rare earth ions local environment changes with heat treatment duration were proposed,based on the emission and lifetime changes.This research will be helpful for the understanding of rare earth doped chalcohalide crystallization mechanism and processes.
基金Funded by the Opening Funding of the State Key Laboratory of Silicate Materials for Architecture (SYSJJ2018-06)the Fundamental Research Funds for the Central Universities Wuhan University of Technology,China (WUT:2016IVA096)+1 种基金the Research Program (No. S2634339) through a Grant Provided by the Ministry of SMEs and Startupsthe Research on Advanced Optical Science and Technology through a Grant Funded by the GIST,Korea。
文摘Ultra-small PbSe quantum dots (QDs) were synthesized using conventional hot-injection method.A small amount of Sn was used as a nucleation promotion agent to control nucleation and growth during the QDs synthesis process.The average diameter of the QDs is about 1.6 nm,of which absorption peak centers at 550 nm and photoluminescence peak centers at 750 nm under 350 nm laser excitation with power as low as 500 μW.Transmission electron microscopy images confirm that the QDs size well matches with the calculated diameter from Brus equation.This match and electron energy loss spectroscopy analysis proves that Sn is not involved into the final structure of the ultra-small PbSe QDs.An ion-exchange process was proposed for the nucleation control and ultra-small QDs synthesis.The prepared ultra-small QDs could be a promising candidate for luminescence,solar cell devices,and others.
