不同Al掺杂对ZnO薄膜结构及光学性质的影响

The influence of different Al concentration doped ZnO thin film on structural and optical properties

采用磁控溅射法(RF)在玻璃衬底上沉积不同Al含量的ZnO薄膜,利用X射线衍射(XRD)、原子力显微镜(AFM)和紫外分光光度计研究了不同浓度的掺杂对薄膜结构和光学性能的影响.结果显示:所有样品都呈现出较强的(002)衍射峰,有较好的c轴择优取向;薄膜表面平整光滑,晶界较明显;薄膜的平均透射率均在85%以上,并随着Al掺杂量的增加而降低;随着Al掺杂量的增加,薄膜的光学带隙值先增大,后减小,吸收边先蓝移,后红移.这与量子限制模型计算结果的变化趋势完全一致.

Al-ZnO films doped with different Al concentration are prepared on glass substrate by RF magnetron sputtering system. The influence of the different Al concentration on the microstructure and optical properties of ZnO films is investigated by using X-ray diffraction（XRD）, atomic force microscopy （AFM） and UV spectrophotometer. The results show that all the samples have a strong diffraction peak and high preferential orientation in the （002） crystallographic direction. There are a very smooth surface and obvious grain boundaries. The transmission spectrum and absorption spectrum of Al-ZnO show that Al-ZnO films possess a transmittance of about 85% in the visible region and the transmittance decrease with increasing Al concentration. The optical band edge shift to a shorter wavelength first as Al is incorporated, and then to a longer wavelength with the increasing of Al content. The optical band gaps calculated based on the quantum confinement model are in good agreement with the experimental values.