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.