厚度对溶胶-凝胶法生长的ZnO薄膜光学性质的影响

Thickness Effect on Optical Properties of ZnO Thin Films Prepared by Sol-gel Process

利用sol-gel旋涂法在普通盖玻片上生长了ZnO薄膜,用光学透射谱、光致发光谱和原子力显微术研究了ZnO薄膜的光学性质和表面形貌.结果发现,在一定薄膜厚度范围内,紫外发光带和光学吸收边均随着薄膜厚度的减小而单调蓝移,且紫外发光强度递增,峰宽变大.综合光致发光谱、光学透射谱和薄膜表面形貌,对薄膜中晶粒尺寸、应力、缺陷等对光学性质的影响进行了讨论.

Zinc oxide （ZnO） thin films were prepared on glass substrates by sol-gel spin-coating method. The optical properties and surface morphologies of the films were investigated using photoluminescence （PL）, optical transmission spectra, and atomic force microscope （AFM）, respectively. The results showed that both the absorption edge and the PL peak blue-shifted with a decrease of thickness of the films, and that PL intensity and linewidth increased for the films with a smaller thickness. The grain sizes, stress, defects in the films resulting in thickness dependence of the optical properties of ZnO were discussed on the basis of the PL, optical transmission, and AFM analyses.