摘要
报道了用MOCVD方法制备的硅基ZnO薄膜中的中性施主-价带D0h发光.ZnO/p-Si结构经空气中700℃退火1h,然后进行X射线衍射(XRD)、光致发光(PL)谱和I-V特性测量.实验得到不同载气流量制备的样品都具有整流特性.深能级瞬态谱(DLTS)测量探测到各样品中存在两个施主深能级E1和E2.相应的室温PL谱测量显示样品近带边发射包含不同的发光线.利用高斯拟合方法,样品S2a的PL谱分解为三条发光线b,c和d,其中发光线b可归结为ZnO中的激子发射;DLTS测量得到的施主能级E1与发光线c和d的局域态电离能Ed相关,为D0h中心.此外,实验揭示E2能级的相对隙态密度与PL谱的发光强度成反比,表明深能级E2具有复合中心性质.
D^0h luminescence of ZnO films deposited on p-type Si substrates grown by MOCVD is reported. After annealing in air at 700℃ for 1h, the photoluminescence （PL） spectra, the I- V characteristics, and the deep level transient spectroscopy （DLTS） of the samples are measured. All the samples we measured have the rectification characteristic. The DLTS signals show two deep levels of E1 and E2. The Gauss fit curves of the PL spectra at room temperature show three luminescence lines,one of which is attributed to the excitation emission. The donor level E1 measured by DLTS and the other two emission lines, which are very close to each other, have a close relation with the location state donor ionization energy Ed, and are thought to be from neutral donors bound to hole emission （Do h）. Moreover, the intensity of the PL spectra decreases while the relative density of E2 increases,showing that E2 has the properties of a nonradiative center.
基金
国家自然科学基金(批准号:50472009
10474091)
中国科学院知识创新工程(批准号:KJCX2-SW-04-02)资助项目~~
