Applications of ZnO nanomaterials in optoelectronics are still limited due to their insufficient photoluminescence efficiency. In order to optimize the photoluminescence properties of ZnO nanorods, the UV emission of ...Applications of ZnO nanomaterials in optoelectronics are still limited due to their insufficient photoluminescence efficiency. In order to optimize the photoluminescence properties of ZnO nanorods, the UV emission of vertically aligned ZnO nanorods grown on a Si substrate, in correlation with Ga＋ ion irradiation at different ion energies （0.5 keV-16 keV）, was investigated in the present study. We found that the UV intensity increased rapidly with increasing Ga＋ ion energy, up to its maximum around 2 keV, at which point the intensity was approximately 50 times higher than that produced by as-grown ZnO nanorods. The gentle bombardment of low-energy Ga＋ ions removes defects from ZnO nanorod surfaces. The Ga＋ ions, on the other hand, implant into the nanorods, resulting in compressive strain. It is believed that the perfect arrangement of the crystal lattice upon removal of surface defects and the introduction of compressive strain are two factors that contribute to the significant enhancement of UV light generation.展开更多
Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formati...Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formation of sulfur nanodots with desired performances.This synthetic strategy allowed for simultaneous size control from 3.2 to 5.6 nm,thus tuning the emission color from ultraviolet(UV)to deep blue(342±430 nm),and for the suppression of unwanted nonradiative recombination centers and deep level emission.The luminescence mechanism and quantum confinement effect of the synthesized sulfur nanodots were investigated by optical spectroscopy and theoretical calculations.These results show promise toward the application of sulfur nanodots in UV optoelectronics,biomedical treatments,and sterilization.展开更多
UV is a high-energy electromagnetic radiation that has been widely used in industrial production and the scientific research domain. In this work, a deep UV light emission was obtained using triboelectrification induc...UV is a high-energy electromagnetic radiation that has been widely used in industrial production and the scientific research domain. In this work, a deep UV light emission was obtained using triboelectrification induced plasma discharge without any extra power supply. By a mechanical friction between polymer and quartz glass, the triboelectric charges cause a changing electric field, which may bring plasma discharge of low pressure gas （Ar-Hg） and give out 253.7 nm irradiation. The UV light caused by continuous friction can excite a trichromatic phosphor and afford a bright white light emission. A UV sterilization experiment shows that -98% of Escherichia coil can be killed in 30 min by UV irradiation, which reveals that a self-powered sterilization apparatus with good sterilization effect was fabricated. This work provides a novel design to fabricate a self- powered UV light emitting device using low-frequency mechanical friction and realizes the coupling of triboelectrificafion and plasma luminescence, which may further expand the application of UV light in special circumstances.展开更多
The ZnO layer with thickness of 1.6 jim in ZnO/ZnGa2O4 composite structure was grown by the thermal oxidation of ZnS sub- strate with gallium. The optical property of the ZnO thick layer was investigated by time-resol...The ZnO layer with thickness of 1.6 jim in ZnO/ZnGa2O4 composite structure was grown by the thermal oxidation of ZnS sub- strate with gallium. The optical property of the ZnO thick layer was investigated by time-resolved photoluminescence. A single UV emission around 375 nm with short lifetime was observed at room temperature while the visible emission was absolutely quenched. The UV emission band was composed of the neutral donor bound exciton （D^0X） and donor-acceptor pair （DAP） emission peaks with large full-width at half-maximums （FWHMs） at 3.367 and 3.318 eV, respectively, at 10 K. However, the intensity of the D^0X emission was stronger than that of the DAP emission at measuring temperatures of 10-300 K.展开更多
基金This research was support by SUG （Start-up funding in NTU）, Tier i （AcRF grant MOE Singapore M401992）, Tier 2 （AcRF grant MOE Singapore M4020159） and the Chinese Natural Science Foundation （Grant 51271031, 60906053, 62174118 and 51308050309）.
文摘Applications of ZnO nanomaterials in optoelectronics are still limited due to their insufficient photoluminescence efficiency. In order to optimize the photoluminescence properties of ZnO nanorods, the UV emission of vertically aligned ZnO nanorods grown on a Si substrate, in correlation with Ga＋ ion irradiation at different ion energies （0.5 keV-16 keV）, was investigated in the present study. We found that the UV intensity increased rapidly with increasing Ga＋ ion energy, up to its maximum around 2 keV, at which point the intensity was approximately 50 times higher than that produced by as-grown ZnO nanorods. The gentle bombardment of low-energy Ga＋ ions removes defects from ZnO nanorod surfaces. The Ga＋ ions, on the other hand, implant into the nanorods, resulting in compressive strain. It is believed that the perfect arrangement of the crystal lattice upon removal of surface defects and the introduction of compressive strain are two factors that contribute to the significant enhancement of UV light generation.
基金financially supported by A*STAR(AME-IRG-A20E5c0083)the National Natural Science Foundation of China(52006005)。
文摘Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formation of sulfur nanodots with desired performances.This synthetic strategy allowed for simultaneous size control from 3.2 to 5.6 nm,thus tuning the emission color from ultraviolet(UV)to deep blue(342±430 nm),and for the suppression of unwanted nonradiative recombination centers and deep level emission.The luminescence mechanism and quantum confinement effect of the synthesized sulfur nanodots were investigated by optical spectroscopy and theoretical calculations.These results show promise toward the application of sulfur nanodots in UV optoelectronics,biomedical treatments,and sterilization.
文摘UV is a high-energy electromagnetic radiation that has been widely used in industrial production and the scientific research domain. In this work, a deep UV light emission was obtained using triboelectrification induced plasma discharge without any extra power supply. By a mechanical friction between polymer and quartz glass, the triboelectric charges cause a changing electric field, which may bring plasma discharge of low pressure gas （Ar-Hg） and give out 253.7 nm irradiation. The UV light caused by continuous friction can excite a trichromatic phosphor and afford a bright white light emission. A UV sterilization experiment shows that -98% of Escherichia coil can be killed in 30 min by UV irradiation, which reveals that a self-powered sterilization apparatus with good sterilization effect was fabricated. This work provides a novel design to fabricate a self- powered UV light emitting device using low-frequency mechanical friction and realizes the coupling of triboelectrificafion and plasma luminescence, which may further expand the application of UV light in special circumstances.
基金supported by the National Natural Science Foundation of China(Grant No.51202191)Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2012JQ6002)Scientific Research Program Funded by Shaanxi Provincial Education Department of China(Grant No.12JK0427)
文摘The ZnO layer with thickness of 1.6 jim in ZnO/ZnGa2O4 composite structure was grown by the thermal oxidation of ZnS sub- strate with gallium. The optical property of the ZnO thick layer was investigated by time-resolved photoluminescence. A single UV emission around 375 nm with short lifetime was observed at room temperature while the visible emission was absolutely quenched. The UV emission band was composed of the neutral donor bound exciton （D^0X） and donor-acceptor pair （DAP） emission peaks with large full-width at half-maximums （FWHMs） at 3.367 and 3.318 eV, respectively, at 10 K. However, the intensity of the D^0X emission was stronger than that of the DAP emission at measuring temperatures of 10-300 K.
