Deposition of Ta2O5 upon silver nanorods as an ultra-thin light absorber

•Ta2O5 was deposited upon Ag nanorod array by glancing angle deposition technique.•The structure exhibits high absorptance for both polarization states.•The enhanced local electric field intensity of structure was investigated.

We report the plasmon-assisted absorption enhancement of an ultra-thin light absorber composed of an Ag nanorod array with Ta2O5 deposited upon each rod. A significant increase in the absorptance efficiency of the plasmonic Ta2O5-capped Ag nanorod array was experimentally observed both in s- and p-polarization states. The causes of the enhanced local electric field intensity were systematically investigated using three-dimensional finite difference time domain. The simulations show that the maximum E-field intensities measured at the end surface of the Ta2O5-capped Ag rod are higher than those obtained from the bare Ag nanorod.