Absorption properties of ordered Cu/AAO nano-array composite structures

Ordered Cu/AAO nano-array composite structures were fabricated by the electrodeposition method within the cylindrical pores of anodic aluminum oxide (AAO) membranes and their optical properties were characterized by absorption spectrum in the range of 200-1000 nm. The experiments show that the surface plasma resonance(SPR) peak appeared around a wavelength of 570 nm, which had a little blue shift and strengthened with the increase of Cu deposition, and gradually disappeared with a larger red shift of the absorption edge over 500 nm. These interesting phenomenon can be well qualitatively described in the framework of the Maxwell-Garnett (M-G) theory. Here, the theoretically analyzed modulation mechanism of the composites' absorption edge expatiates the absorption peak disappearance with the increase of Cu deposition.