A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its plati...A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.展开更多
The influence of preparation methods on the photoluminescence properties of ZnO film was studied.Two methods were applied to fabricate ZnO films in a conventional pulsed laser deposition apparatus.One is high temperat...The influence of preparation methods on the photoluminescence properties of ZnO film was studied.Two methods were applied to fabricate ZnO films in a conventional pulsed laser deposition apparatus.One is high temperature(500-700 ℃)oxidation of the metallic zinc film that is obtained by pulsed laser deposition.The other is pulse laser ablation of Zn target in oxygen atmosphere at low temperature(100-250 ℃).The photoluminescence property was detected by PL spectrum.The room temperature PL spectra of the ZnO films obtained by oxidation method show single violet luminescence emission centered at 424 nm(or 2.90 eV)without any accompanied deep-level emission and UV emission.The violet emission is attributed to interstitial zinc in the films.Nanostructure ZnO film with c-axis(002)orientation is obtained by pulsed laser deposition.The ZnO film deposited at 200 ℃ shows single strong ultraviolet emission.The excellent UV emission is attributed to the good crystalline quality of the film and low intrinsic defects at such low temperature.展开更多
Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quan...Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quantum efficiency of freshly prepared PbS QDs （7%-11%） remained higher than 5% upon aging for three weeks when the nanocrystals （NCs） were stored in an ice-bath in the dark, and higher than 5%for at least five weeks when extra DTG ligands were introduced into the nanocrystal solution followed by stirring every two weeks. Poly（N-isopropyl acrylamide） （PNIPAM） microgels were produced via precipitation polymerization with dimensions of ca. 230 nm and polydispersity of 3-5%. Incorporation of PbS QDs into PNIPAM microgels indicated that PbS can be incorporated into the interior of microgel particles and not at the microgel interface. The combination of reasonable room temperature quantum efficiency and strong, efficient luminescence covering the 1.3-1.55 μm telecommunication window makes these nanoparticles promising materials in optical devices and telecommunications.展开更多
The optical properties of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of t...The optical properties of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of the differences in their molecular structures, the dilute solutions(about 1×10-6 M) of these substituted polyacetylenes exhibit the same absorptions and deep-blue emissions(about 360 nm). Interestingly, the absorption and emission spectra of these substituted polyacetylenes are similar to those of the small molecule carbazole. As the concentration of the substituted polyacetylenes increases to about 1×10-6 M, we have detected intense blue emissions at about 475 nm. Our results indicate that the absorption, the deep-blue emission(about 360 nm) and the intense blue emission(about 475 nm) originate from the carbazole chromophores in the side chain.展开更多
Thin films of ZnO were electrodeposited from an aqueous solution of Zn（NO3 ）2 on indium tin oxide（ITO）-covered glass substrate. The analysis of X-ray diffraction（XRD） and scanning electron micrograph （SEM） ind...Thin films of ZnO were electrodeposited from an aqueous solution of Zn（NO3 ）2 on indium tin oxide（ITO）-covered glass substrate. The analysis of X-ray diffraction（XRD） and scanning electron micrograph （SEM） indicated that the obtained ZnO films had a compact hexagonal wurtzite type structure with preferable （002） growth direction. A sharp near-UV emission peak located at 380 nm and a strong orange-red emission peak located at 593 nm were observed in the photoluminescence, when excited with 325 nm wavelength at room temperature. Then the prepared ZnO films were introduced as anode phosphors into the field emission test. It was found that orange-red cathode-luminescence was observed and the luminescent brightness was enhanced by annealing. When annealing temperature increased about 600 ℃, the photoluminescence with peak of 531 nm and the green cathode-luminescence were observed. The tests showed that the brightness of about 2 × 102 cd/m^2 was obtained at electric field of 2 V/μm for annealed sample. The results revealed that the film could be a good kind of low-voltage drived cathode-luminescence phosphor.展开更多
In the present work the photoluminescence character of sapphire implanted with inert gas ions was studied. Sapphire single crystals were implanted with 120keV He or Ar ion at 600 K to fluences ranging from 5×10^1...In the present work the photoluminescence character of sapphire implanted with inert gas ions was studied. Sapphire single crystals were implanted with 120keV He or Ar ion at 600 K to fluences ranging from 5×10^16 to 2×10^17 ions/cm^2. PL spectra in pristine and ion-implanted specimens were measured using 340nm excitation. PL peak at 370 nm and 440 nm is observed. From the PL spectra obtained from He-implanted specimens (Fig.l), a blue-violet PL band with a maximum at about 440 nm was created in the No.1 sample of 5×10^16 ions/cm^2, this spectrum depends strongly on the fluence of He^+ ions. At higher dose, with increasing the concentration of helium, the PL peak is nearly pristine. From Fig.2, it is clearly seen that the PL peak intensity increases with implantation time as in No.3 sample. We think the PL peak at 440 nm was induced by the formation of He bubbles and point defects. From Fig.1 to Fig.2 their character expression was the same, but their photoluminescence mechanism was regarded to be different.展开更多
In 2003, 200 kV heavy ion accelerator was operated for i 100 h for the study on ion implantation modification. The improvement and maintenance of the accelerator wcrc made. 8 species of ion bcarns wcrc provided. They ...In 2003, 200 kV heavy ion accelerator was operated for i 100 h for the study on ion implantation modification. The improvement and maintenance of the accelerator wcrc made. 8 species of ion bcarns wcrc provided. They are H^+, He^+, Ne^+, C^+, N^+, Ar^+, Fe^+ and Cu^+. In 2003, 13 physics experiments wcrc performed on this accelerator.展开更多
Gallium Nitride (GaN) is an important material for the development of novel short-wave-length photonicdevices or high-frequency, high-power electronic devices. Ion implantation/irradiation was proved to be an effectiv...Gallium Nitride (GaN) is an important material for the development of novel short-wave-length photonicdevices or high-frequency, high-power electronic devices. Ion implantation/irradiation was proved to be an effective method to modify the physical properties of the material. In the present work, we studied the dependence of damage accumulation on irradiation dose and temperature and the corresponding effects on photolumines cence character of the material. Specimens of GaN (n-type doping, (0001) on axis) were irradiated with展开更多
基金Project(50473046) supported by the National Natural Science Foundation of ChinaProject(204097) supported by the Science Foundation of the Ministry of Education of China+1 种基金Project(04JJ1002) supported by the Outstanding Youth Foundation of Hunan Province,ChinaProject(06JJ2008) supported by the Natural Science Foundation of Hunan Province,China
文摘A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated. A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about 、5.69 and 、3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material.
基金Project(2004CB619301)supported by the National Basic Research Program of ChinaProject supported by 985-Automotive Engineering of Jilin University
文摘The influence of preparation methods on the photoluminescence properties of ZnO film was studied.Two methods were applied to fabricate ZnO films in a conventional pulsed laser deposition apparatus.One is high temperature(500-700 ℃)oxidation of the metallic zinc film that is obtained by pulsed laser deposition.The other is pulse laser ablation of Zn target in oxygen atmosphere at low temperature(100-250 ℃).The photoluminescence property was detected by PL spectrum.The room temperature PL spectra of the ZnO films obtained by oxidation method show single violet luminescence emission centered at 424 nm(or 2.90 eV)without any accompanied deep-level emission and UV emission.The violet emission is attributed to interstitial zinc in the films.Nanostructure ZnO film with c-axis(002)orientation is obtained by pulsed laser deposition.The ZnO film deposited at 200 ℃ shows single strong ultraviolet emission.The excellent UV emission is attributed to the good crystalline quality of the film and low intrinsic defects at such low temperature.
基金NSFC(No.50543007)Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)+1 种基金NSF of Guangdong Province (No.07006838)Tianhe Bureau of Sci. & Techno., Guangzhou.
文摘Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quantum efficiency of freshly prepared PbS QDs （7%-11%） remained higher than 5% upon aging for three weeks when the nanocrystals （NCs） were stored in an ice-bath in the dark, and higher than 5%for at least five weeks when extra DTG ligands were introduced into the nanocrystal solution followed by stirring every two weeks. Poly（N-isopropyl acrylamide） （PNIPAM） microgels were produced via precipitation polymerization with dimensions of ca. 230 nm and polydispersity of 3-5%. Incorporation of PbS QDs into PNIPAM microgels indicated that PbS can be incorporated into the interior of microgel particles and not at the microgel interface. The combination of reasonable room temperature quantum efficiency and strong, efficient luminescence covering the 1.3-1.55 μm telecommunication window makes these nanoparticles promising materials in optical devices and telecommunications.
基金The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars ,State Education Ministry ,2005Natural Science Foundation of Guangdong Province(5300568)+1 种基金Key Scienceand Technology Research Foundation of State Education Ministry (206110)National Natural ScienceFoundation of China(10674091)
文摘The optical properties of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of the differences in their molecular structures, the dilute solutions(about 1×10-6 M) of these substituted polyacetylenes exhibit the same absorptions and deep-blue emissions(about 360 nm). Interestingly, the absorption and emission spectra of these substituted polyacetylenes are similar to those of the small molecule carbazole. As the concentration of the substituted polyacetylenes increases to about 1×10-6 M, we have detected intense blue emissions at about 475 nm. Our results indicate that the absorption, the deep-blue emission(about 360 nm) and the intense blue emission(about 475 nm) originate from the carbazole chromophores in the side chain.
基金Science and Technology Foundation of Education Ministry of China(205091)
文摘Thin films of ZnO were electrodeposited from an aqueous solution of Zn（NO3 ）2 on indium tin oxide（ITO）-covered glass substrate. The analysis of X-ray diffraction（XRD） and scanning electron micrograph （SEM） indicated that the obtained ZnO films had a compact hexagonal wurtzite type structure with preferable （002） growth direction. A sharp near-UV emission peak located at 380 nm and a strong orange-red emission peak located at 593 nm were observed in the photoluminescence, when excited with 325 nm wavelength at room temperature. Then the prepared ZnO films were introduced as anode phosphors into the field emission test. It was found that orange-red cathode-luminescence was observed and the luminescent brightness was enhanced by annealing. When annealing temperature increased about 600 ℃, the photoluminescence with peak of 531 nm and the green cathode-luminescence were observed. The tests showed that the brightness of about 2 × 102 cd/m^2 was obtained at electric field of 2 V/μm for annealed sample. The results revealed that the film could be a good kind of low-voltage drived cathode-luminescence phosphor.
文摘In the present work the photoluminescence character of sapphire implanted with inert gas ions was studied. Sapphire single crystals were implanted with 120keV He or Ar ion at 600 K to fluences ranging from 5×10^16 to 2×10^17 ions/cm^2. PL spectra in pristine and ion-implanted specimens were measured using 340nm excitation. PL peak at 370 nm and 440 nm is observed. From the PL spectra obtained from He-implanted specimens (Fig.l), a blue-violet PL band with a maximum at about 440 nm was created in the No.1 sample of 5×10^16 ions/cm^2, this spectrum depends strongly on the fluence of He^+ ions. At higher dose, with increasing the concentration of helium, the PL peak is nearly pristine. From Fig.2, it is clearly seen that the PL peak intensity increases with implantation time as in No.3 sample. We think the PL peak at 440 nm was induced by the formation of He bubbles and point defects. From Fig.1 to Fig.2 their character expression was the same, but their photoluminescence mechanism was regarded to be different.
文摘In 2003, 200 kV heavy ion accelerator was operated for i 100 h for the study on ion implantation modification. The improvement and maintenance of the accelerator wcrc made. 8 species of ion bcarns wcrc provided. They are H^+, He^+, Ne^+, C^+, N^+, Ar^+, Fe^+ and Cu^+. In 2003, 13 physics experiments wcrc performed on this accelerator.
文摘Gallium Nitride (GaN) is an important material for the development of novel short-wave-length photonicdevices or high-frequency, high-power electronic devices. Ion implantation/irradiation was proved to be an effective method to modify the physical properties of the material. In the present work, we studied the dependence of damage accumulation on irradiation dose and temperature and the corresponding effects on photolumines cence character of the material. Specimens of GaN (n-type doping, (0001) on axis) were irradiated with
