【作者】 陶亚明；

【导师】 马书懿；

【作者基本信息】 西北师范大学 ， 凝聚态物理， 2011， 硕士

【摘要】 ZnO是一种Ⅱ-Ⅵ族直接带隙宽带半导体,室温禁带宽度约为3.37eV,激子束缚能高达60meV。在大气条件下,ZnO具有六方纤锌矿结构。作为新一代的宽带半导体材料,ZnO具有优异的光学、电学及压电特性,在发光二极管、光探测器、电致荧光器件、透明导电薄膜、表面声波器等诸多领域有着广泛的应用。本文采用射频磁控溅射方法在玻璃和硅（100）衬底上制备了不同氧分压的Cu掺杂ZnO（ZnO:Cu）薄膜。利用X射线衍射（XRD）、原子力显微镜（AFM）和光致荧光发光（PL）等表征技术,研究了衬底和氧分压对ZnO:Cu薄膜的结晶性能和光学特性的影响。从而为ZnO薄膜的应用提供一些实验数据和理论基础。主要研究结果如下:1、在研究Si衬底,氧分压对ZnO:Cu薄膜结构特性的影响中发现:随着氧分压的增加,薄膜的（002）衍射峰先增强后减弱,表明氧分压可以影响ZnO:Cu薄膜的结晶取向。并且薄膜的压应力随着氧分压的增加,先增加后减小。2、通过紫外分光光度计对样品室温光致发光特性的研究,我们观察到一个紫光峰、两个蓝光峰和一个绿光峰。分析表明,峰位在401nm的紫光峰与表面带隙有关;峰位在449nm和484nm的蓝光发光峰可能与电子从Zni到价带顶之间的跃迁和电子从Zn_i到V_Zn之间的跃迁有关;峰位在530nm附近的绿光峰可能与氧空位有关。3、对比研究了在玻璃沉底和硅衬底上氧分压对ZnO:Cu薄膜的结晶性能和光学特性的影响。结果显示薄膜沉积在Si衬底上比玻璃衬底上有更好c轴择优取向,两种衬底上沉积的薄膜有相同的氧分压c轴结晶规律,且在氧氩比为10:10时,薄膜c轴取向同时达到最好。通过对光致发光的研究表明,在低氧环境时玻璃衬底较容易制得好的发光薄膜,可在富氧环境时Si衬底上制得的薄膜发光性能较好。更多还原

【Abstract】 Zinc oxide (ZnO) is an importantⅡ-Ⅵdirect band gap semiconductor material, which has band gap of 3.37eV at room temperature (RT), and the exciton binding energy as high as 60meV. Usually ZnO has hexahedron wurtzite structure at the air condition. It has been investigated extensively due to its distinguished performance in electrical, optical and piezoelectric properties making suitable for many applications such as light emitting diodes, photodetectors, electroluminescence, transparent conductive film, surface acoustic waves device and so on.Cu-doped ZnO (ZnO:Cu) films are prepared on glass and Si(100) substrates at different oxygen partial pressures by radio frequency reactive magnetron sputtering technique. The effect of various substrate and oxygen partial pressures on the crystalline and optical properties of ZnO:Cu thin films were investigated by the X-ray diffraction(XRD), atomic force microscopy(AFM) and fluorescence spectro- photometer. In this way some experimental data and the theoretical basis are provided for the application of ZnO films. The results are summarized as follows:1、The influence of oxygen partial pressure on the micro-structural property of ZnO:Cu films have been studied on Si substrates. The results indicated that the intensity of (002) diffraction peak first increased and then decreased With the oxygen partial pressure increased, which indicated that oxygen partial pressure can influence crystallization orientation of ZnO:Cu films. And with increasing oxygen partial pressure, the compressive stress of the films increased first and then decreased.2、The photoluminescence (PL) of the samples were measured at room temperature. A violet peak, two blue peaks and a green peak were observed from the PL spectra of the four samples. The analysis of PL spectra showed that the green emission peak (530nm) originated from electron transition from deep donor level by the oxygen vacancies to valence band; two blue emission peaks (449nm and 484nm) were assigned to the electron transition from both the interstitial Zn levels to valence band and the energy levels of interstitial Zn to Zn vacancies; and the violet emission peak (401nm) relate interface traps existing at the grains boundaries.3、The effect of oxygen partial pressures on the crystalline and optical properties of ZnO:Cu thin films which prepared on glass and Si(100) substrates were Comparatively investigated. The results indicated that films deposited on Si substrates have a better c-axis preferred orientation than glass substrate. The films deposited on the various substrates have the same crystal law with increasing of oxygen partial pressure,and as the ratio of oxygen and argon is increased to 10:10, the c-axis growth orientation of films achieve the best at the same time. Study on photoluminescence have shown that films prepared on the glass substrate have better light-emitting in poor oxygen environment, whereas films prepared on the Si substrate have better PL properties than on the glass substrate in rich oxygen environment.更多还原