An absorption element for absorbing radiation incident on the element at a certain wavelength band. The element includes a surface defining a normal direction perpendicular to the surface. The element also includes an array of a plurality of spaced apart nano-pillars extending from the surface at an angle orientation other than the normal direction, which creates angular asymmetry so as to increase the element's absorption response in a particular direction. The nano-pillars are made of a suitable semiconductor material and have a size relative to the wavelength band to absorb the radiation. In one non-limiting embodiment, the nano-pillars are angled at 45° relative to the normal direction and are cone-shaped to broaden their absorption capabilities.