中国科学院机构知识库网格系统: 检索

The photoluminescence characteristics of TiO2 and its relation with photocatalysis reaction on Pt/TiO2 会议论文 OAI收割
4th asia pacific congress on catalysis, 新加坡, 2006-12-6
石建英; 陈均; 冯兆池; 应品良; 李灿

收藏 | 浏览/下载：17/0 | 提交时间：2011/07/11

Photoluminescence of inert-gas ion implanted sapphire after 230-MeV Pb ion irradiation 会议论文 OAI收割
作者: Zhang, CH; Wang, ZG; Zhao, ZM; Sun, YM; Duan, JL

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收藏 | 浏览/下载：5/0 | 提交时间：2018/08/20

ion implantation heavy ion irradiation Al2O3 PL spectra

Photoluminescence of inert-gas ion implanted sapphire after 230-MeV Pb ion irradiation 会议论文 OAI收割
作者: Duan, JL; Song, Y; Zhang, CH; Wang, ZG; Sun, YM

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收藏 | 浏览/下载：8/0 | 提交时间：2018/08/20

ion implantation heavy ion irradiation Al2O3 PL spectra

Effect of interface on luminescence properties in ZnO/MgZnO heterostructures (EI CONFERENCE) 会议论文 OAI收割
Wei Z. P.; Lu Y. M.; Shen D. Z.; Wu C. X.; Zhang Z. Z.; Zhao D. X.; Zhang J. Y.; Fan X. W.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

A set of ZnO/MgZnO heterostructures with well widths Lw varying from 2 to 20 nm has been grown by plasma-assisted molecular-beam epitaxy (P-MBE). We present a room-temperature (RT) study of the well-width-dependent photoluminescence (PL) spectra and carrier lifetimes in ZnO/MgZnO heterostructures. Bi-exponential process is seen at RT time-decay curves of the luminescence from the well layers. The fast process is from the recombination of the free exciton while the slow process is attributing to the recombination of the localized exciton in the interface of ZnO and MgZnO. It is also confirmed from the PL peak shift of time-resolved PL spectra. With decreasing the well thickness the fast process gradually increases and dominantly contributes to the PL spectrum due to the interface improvement. 2006 Elsevier B.V. All rights reserved.

Temperature-enhanced ultraviolet emission in ZnO thin film (EI CONFERENCE) 会议论文 OAI收割
Zhang Y. J.; Xu C. S.; Liu Y. C.; Liu Y. X.; Wang G. R.; Fan X. W.

收藏 | 浏览/下载：14/0 | 提交时间：2013/03/25

We have studied the structural and optical properties of ZnO thin films prepared by thermal oxidation of ZnS films deposited by plasma assisted electron-beam evaporation on Si(1 0 0) substrates. The transformation from zinc blende ZnS to hexagonal wurtzite ZnO is confirmed by Raman and X-ray diffraction (XRD) measurement. For the sample thermally oxidized at 600 C for 2 h a novel UV emission peak Ix located at 3.22 eV (385 nm) has been observed. The temperature-dependent photoluminescence spectra show that the integrated intensity of Ix increases exponentially with increasing temperatures within the measuring temperature range from 80 to 300 K but the peak position remains nearly constant. We explain this behavior in terms of electron tunneling into the radiative recombination centers.

Excitonic properties of vertically aligned ZnO nanotubes under high-density excitation (EI CONFERENCE) 会议论文 OAI收割
Lu Y. M.; Liang H. W.; Shen D. Z.; Zhang Z. Z.; Zhang J. Y.; Zhao D. X.; Liu Y. C.; Fan X. W.

收藏 | 浏览/下载：10/0 | 提交时间：2013/03/25

In this paper highly oriented and vertically arranged ZnO nanotubes are prepared on Al2O3 (0 0 0 1) substrate without employing any metal catalysts by plasma-assisted molecular beam epitaxy. The photoluminescence (PL) spectra at room temperature are studied under high excitation densities. Under lower excitation density (60 kW/cm2) PL spectrum shows that one strong free exciton emission (FE) locates at 3.306 eV. As the excitation density increases up to 200 kW/cm2 a new emission peak (Pn) located at low-energy side of FE is attributed to the spontaneous emission due to an exciton-exciton (Ex-E x) scattering process from two ground state excitons where one exciton is recombined by emitting a photon and the other is scattered into the excited states of n=2 3 4.... Under excitation density of 300 kW/cm 2 the stimulated emission originating from Ex-E x scattering is obtained. When the excitation density is above 580 kW/cm2 the emission from electron-hole plasma is observed in low-energy side of the P band and indicates a typical superradiation recombination processes with increasing excitation density. 2006 Elsevier B.V. All rights reserved.

Temperature dependence of carrier transfer and exciton localization in ZnO/MgZnO heterostructure (EI CONFERENCE) 会议论文 OAI收割
作者: Zhang J.; Zhang J.; Zhang J.; Li B.; Li B.

收藏 | 浏览/下载：10/0 | 提交时间：2013/03/25

MgZnO/ZnO heterostructure was fabricated on sapphire substrate by plasma assistant molecular beam epitaxy. The micro-photoluminescence spectra of sample are reported which shows that different emission peaks would appear when the laser beam focuses different deepness in the film. A carrier tunneling process from the MgZnO capping layer to ZnO layer was observed by the measured temperature dependence of photoluminescence spectra. This induces the emission intensity of the ZnO grew monotonically from 81 to 103 K. 2006 Elsevier B.V. All rights reserved.

The study of optical property for CdS nanocrystalline prepared by precipitation method (EI CONFERENCE) 会议论文 OAI收割
ICO20: Materials and Nanostructures, August 21, 2005 - August 26, 2005, Changchun, China
作者: Zhang S.; Li W.; Li W.

收藏 | 浏览/下载：15/0 | 提交时间：2013/03/25

CdS nanocrystalline were prepared by precipitation from a mixture of aqueous solutions of cadmium salts and sulfur salts without adding any surface-termination agent. Their crystal structures and particle sizes were determined by X-ray diffraction (XRD). The CdS nanocrystalline precipitated from different precursors exhibited three cases: cubic phase hexagonal phase and a mixture of cubic and hexagonal phases. The photoluminescence (PL) of cadmium salt precursors and CdS nanocrystalline is also analyzed. Similar spectral band structure of cadmium salt precursors and CdS nanocrystalline is found. The spectral intensity of the CdS-Cd rich and CdS-S rich nanocrystalline shows that the precursors themselves have important effect on the PL of CdS nanocrystalline.

Optical characterization of bare CdSe and CdSe/CdS core/shell nanocrystals (EI CONFERENCE) 会议论文 OAI收割
ICO20: Biomedical Optics, August 21, 2005 - August 26, 2005, Changchun, China
作者: Liu L.; Yu B.; Liu L.

收藏 | 浏览/下载：7/0 | 提交时间：2013/03/25

Thiol-capped CdSe/CdS core/shell nanocrystals (NCs) which show high luminescence quantum yield are synthesized in an aqueous solution. UV-Vis absorption spectroscopy and photoluminescence (PL) spectroscopy are employed to analyze optical characters and stabilities of NCs. Furthermore PL properties are studied in a temperature range between 77K and 300K. The PL peak position of bare CdSe NCs shifts toward shorter wavelengths and the band becomes sharper with decreasing temperature. On the same condition the PL peak position of CdSe/CdS core/shell NCs keeps unconverted nearly with the variation of temperature. Photostability of bare CdSe NCs and CdSe/CdS core/shell NCs are compared under the 325nm laser irradiation. It takes 78 seconds that the PL intensity declines to the half for CdSe NCs but 442 seconds for CdSe/CdS core/shell NCs. The fluorescence decay lifetime increases about six times after overcoating. The results indicate that the CdS shell can improve the low temperature PL stability and photostability of CdSe NCs effectively.

Field emission properties of ZnO nanowires (EI CONFERENCE) 会议论文 OAI收割
ICO20: Display Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China
Meng X. Q.; Shen D. Z.; Zhang J. Y.; Zhao D. X.; Lu Y. M.; Zhang Z. Z.; Fan X. W.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

ZnO nanowires were obtained by using a simple vapor solid process. The length of the nanowires is about 1 m with diameters ranging from 40 nm to 150 nm. X-ray diffraction (XRD) pattern confirms the nanowires are wurtzite structure with c-axis preferred orientation. Photoluminescence (PL) measurement shows a strong UV emission and a weak visible emission. Field emission (FE) results proved the nanowires have low turn-on voltage and high field enhancement factor which indicates ZnO nanowire is a suitable candidate for field emission display.