Co/AAO纳米有序阵列复合结构的光致发光和光吸收特性

以草酸电解液制备的高度有序的纳米级多孔阳极氧化铝(AAO)为模板,采用交流电化学沉积工艺合成了Co/AAO纳米有序阵列复合结构。分别研究了AAO模板和Co/AAO结构的光致发光和光吸收特性。结果表明,AAO模板在350～550nm范围内存在较强的光致发光带,其峰位在395nm处;Co/AAO纳米有序阵列复合结构的光致发射峰位亦在395nm处,且发光峰强度随Co沉积量的增加而迅速减弱。实验发现,Co/AAO纳米有序阵列复合结构的光吸收边从近紫外至近红外的波段范围内发生大幅度红移,最大红移量甚至超过380nm。文章定性分析并解释了Co/AAO纳米有序阵列复合结构吸收边大幅度红移及其光发射峰位不变、而峰强减弱的主要原因。

The Photoluminescence and Absorption Properties of Co/AAO Nano-Array Composites

Ordered Co/AAO nano-array structures were fabricated by alternating current(AC) electrodeposition method within the cylindrical pores of anodic aluminum oxide(AAO) template prepared in oxalic acid electrolyte.The photoluminescence(PL) emission and photoabsorption of AAO templates and Co/AAO nano-array structures were investigated respectively.The results show that a marked photoluminescence band of AAO membranes occurs in the wavelength range of 350-550 nm and their PL peak position is at 395 nm.And with the increase in the deposition amount of Co nanoparticles,the PL intensity of Co/AAO nano-array structures decreases gradually,and their peak positions of the PL are invariable(395 nm).Meanwhile the absorption edges of Co/AAO show a larger redshift,and the largest shift from the near ultraviolet to the infrared exceeds 380 nm.The above phenomena caused by Co nano-particles in Co/AAO composite were analyzed.