composite film was deposited on glass substrates by means of sol-gel method. The crystal structure and morphology of samples were characterized by X-ray diffraction (XRD)
transmission electron microscope (TEM) and scanning electron microscope (SEM)
respectively. The transmittance and photoluminescent properties of ZnO/SiO
2
composite film with different concentration of ZnO were studied. The results indicated that the composite film is composed of SiO
2
and ZnO two kinds of oxide after annealed in air at 500 ℃
and the crystal particle size calculated by Scherrer formula is 18.7 nm. The results of SEM showed that two-layer structure can be observed clearly. Selected area diffraction (SAED) indicated that the structure of ZnO/SiO
2
composite film is polycrystal. Transmittance of film decreases with the content of ZnO increasing
and the band gap diminishes from 3.5 eV to 3.2 eV
which indicates that optical absorption edge moved to long wavelength. The PL spectra show there are two luminescence locations under 355 nm light excitation
one is the broad emission peaked at 384 nm and the other is the blue band peaked at 440 nm. Both of them are attributed to the electron-hole recombination and defect luminescence of ZnO
respectively. In this paper
the coating method is that two kinds of solution are coated
respectively. So
the two-layer structure of ZnO/SiO
2
composite film must be considered. As there is a ZnO/SiO
2
interface in the two-layer film
so the structure defect
bond defect and the deep level centers caused by crystal lattice aberrance would be formed after annealed at 500 ℃
these defects and deep level centers can influence the photoluminescent properties of composite film in a certain extent. At the same time
defect center (O—Si—O) of oxygen deficiency in SiO
2
could contribute to the blue emission
too.
关键词
Keywords
references
. Yuan Ningyi, He Zejun, Zhao Changning, et al. Study of optical properties of nano-scale ZnO and ZnO-SiO2 thin films [J]. Acta Phys. Sin.(物理学报), 2008, 57 (4):2537-2542 (in Chinese).
. Li J H, Shen D Z, Zhang J Y, et al. The effect of Mn2+ doping on strcuture and photoluminescence of ZnO nanofilms synthesized by sol-gel method [J]. J. Lumin., 2007, 122-123 :352-354.
. Zeng Y J, Ye Z Z, Xu W Z, et al. Study on the Hall-effect and photoluminescence of N-doped p-type ZnO thin films [J]. Materials Lett., 2007, 61 (1):41-44.
. Xu Ziqiang, Deng Hong, Xie Juan, et al. Al-doping effects on optical properties of c-axis orientated ZnO ∶ Al thin films prepared by the sol-gel method [J]. J. Optoelectronics ·Laser (光电子·激光), 2006, 17 (3):257-260 (in Chinese).
. Fu Zhuxi, Lin Bixia. Important problems of studying photo-electronic ZnO films [J]. Chin. J. Lumin. (发光学报), 2004, 25 (2):117-121 (in Chinese).
. Shintaro Miyanishi, Motoji Yagura, Nobuaki Teraguchi, et al. Huge magnetoresistive effects using space charge limited current in ZnO/SiO2 system [J]. Appl. Phys. Lett., 2007, 91 (19):192104-1-3.
. Parmod S, Shishodia P K, Mehra R M, et al. Photoluminescence and absorption in sol-gel-derived ZnO films [J]. J. Lumin., 2007, 126 (2):800-806.
. Xie Lunjun, Chen Guangde, Zhu Youzhang, et al. Different luminescence behavior between the surface and edge of ZnO film [J]. Chin. J. Lumin. (发光学报), 2006, 27 (6):910-916 (in Chinese).
. Shi Chaoshu, Zhang Guobin, Chen Yonghu, et al. Special spectroscopic properties of ZnO thin film and its mechanisms [J]. Chin. J. Lumin. (发光学报), 2004, 25 (3):272-276 (in Chinese).
. Xie Lunjun, Chen Guangde, Zhou Youzhang, et al. Photoluminescence characteristics of ZnO film grown by laser-MBE method [J]. Chin. J. Lumnin.(发光学报), 2006, 27 (2):215-220 (in Chinese).
. Liu Dali, Du Guotong, Wang Jinzhong, et al. Characteristics of nitrogen doped ZnO film [J]. Chin. J. Lumin. (发光学报), 2004, 25 (2):134-138 (in Chinese).
. Chen Yiqing, Zhang Kun, Wang Bing, et al. Vapor-phase synthesis and photoluminescence of amorphous SiO2 nanowires [J]. J. Function Materials (功能材料), 2004, 25 (2):134-138 (in Chinese).