溶胶-凝胶法纳米ZnO薄膜的绿光发射

利用溶胶-凝胶法制备了纳米ZnO薄膜,室温下测量了样品的光致发光谱(PL)和X射线衍射谱(XRD),观测到中心波长在523 nm附近的绿色荧光发射,研究了纳米ZnO薄膜的绿光发射机制,证实了纳米ZnO薄膜绿光可见发射带来自氧空位(Vo)形成的浅施主能级和锌空位(Vzn)形成的浅受主能级之间的复合。

Green Emission of Nanocrystalline ZnO Films by Sol-Gel Process

Nanocrystalline ZnO films is prepared by using sol-gel process.ZnO films grow on a quartz glass subtractes.Photoluminescence spectra of nanocrystalline ZnO films with excitation wavelength 365 nm are measured at room temperature.Green emission is observed,its central wavelength is 523 nm.Crystal structure of samples is examined by X-ray diffraction(XRD) pattern,the mean grain size of nanocrystalline ZnO films are calculated by with Debye-Scherrer formula.The results indicate that nanocrystalline ZnO films have a hexagonal wurtzite structure and polycrystalline and show sharp diffraction peak for ZnO(002),which indicate that as-sputered film was highly c-axis oriented.The mechanism behind the Green emission is also discussed.The experiments prove that the luminescence emission peak located 523nm corresponds to the transition from the shallow level of oxygen vacancy to the shallow level of zinc vacancy.