超薄多孔阳极氧化铝薄膜的制备和光学特性

Preparation and Optical Properties of Ultrathin Porous Anodic Alumina Film

采用二步阳极氧化法在草酸溶液中制备了超薄的多孔阳极氧化铝（PAA）薄膜，借助于扫描电子显微镜（SEM）分析了多孔阳极氧化铝薄膜的微观形貌，发现在其表面孔径为70～90nm的六边形内孔洞分布均匀，且垂直于表面平行生长，厚度约为500nm。对其光致发光性能研究发现，该薄膜具有一个位于395nm的紫外波段的发光峰。分析表明，该发光现象起源于氧化铝薄膜中与氧空位相关的F^＋中心。透射率随着波长的增加先急剧增加，在波长大于300nm时，透射率随着波长的增加缓慢减小；而吸收率随着波长的增加先急剧减小，在波长大于300nm时，吸收率随着波长的增加缓慢增加。

The highly ordered porous anodic alumina（PAA） films were fabricated by twostep anodizing process in oxalic acid solution. The morphology of the PAA films were investigated by scanning electron microscopy. It was found that the hexagonal pores grown in PAA with diameters of 70-90 nm are highly ordered and pack with each other closely, and the thickness is about 500 nm. Photoluminescence （PL） measurements show that the PAA films obtained have a ultraviolet PL band with a peak position at around 395 nm. The 395 nm ultraviolet luminescence band could be attributed to the F^＋ centres existed in the PAA films formed in oxalic acid solutions. Tansmissivity increases as the wavelength increases, at wavelength more than 300 nm, transmissivity decreases slowly as the wavelength increases,absorptance decreases sharply as the wavelength increases, at wavelength more than 300 nm, absorptance increases slowly as the wavelength increases.