Aspect ratio-dependent optical properties of Ni–P/AAO nano-array composite structure

摘要

Using electrochemical deposition, Ni–P nanorod arrays with a series of aspect ratios have been successfully fabricated in the pores of anodic aluminum oxide (AAO) membranes. The aspect ratio of Ni–P nanorods was controlled by the deposition time. The morphologies were analyzed by scanning electron microscopy and transmission electron microscopy. The dependence of the optical absorbance upon the aspect ratio was studied by UV–vis spectra. The results show that the absorbance increases in visible region and decreases rapidly in ultraviolet region as the aspect ratio of nanorods increases, which qualitatively agree with the prediction of Maxwell–Garnett (MG) theory and the simulation based on the Mie scattering theory, respectively. The dependence of photoluminescence emission (PL) spectra upon the aspect ratio is also obtained. These investigations show that the optical properties of nano-array composite structure can be modified by changing the aspect ratio of nanorods.