Tradional antireflection coatings composed of dielectric layers usually require the thickness to be larger than quarter wavelength. Here, we demonstrate that materials with permittivity or permeability dominated by imaginary parts, i.e. lossy or gain media, can realize non-resonant antireflection coatings in deep sub-wavelength scale. Interestingly, while the reflected waves are eliminated as i...

Water-related energy is an inexhaustible and renewable energy resource in our environment, which has huge amount of energy and is not largely dictated by daytime and sunlight. The transparent characteristic plays a key role in practical applications for some devices designed for harvesting water-related energy. In this paper, a highly transparent triboelectric nanogenerator (T-TENG) was designe...

Vanadium dioxide (VO2) is a Mott phase transition compound that can be applied as a thermochromic smart material for energy saving and comfort, and titanium dioxide (TiO2) is a well-known photocatalyst for self-cleaning coatings. In this paper, we report a VO2@TiO2 core-shell structure, in which the VO2 nanorod core exhibits a remarkable modulation ability for solar infrared light, and the TiO2...

We constructed polarization-selective computer-generated holograms that apply an independent phase profile during readout by horizontal and vertical light polarizations. These elements are composed of two surface-relief-etched birefringent substrates joined face to face. We describe the design methodology for arbitrary birefringent substrate and gap materials. We show how these holograms are fa...

Nanostructured active or absorbing layers of solar cells, including photonic crystals and wire arrays, have been increasingly explored as potential options to enhance performance of thin film solar cells because of their unique ability to control light. We show that 2D photonic crystals can improve light trapping by an enhanced density of optical states and improved incoupling, and demonstrate,...

A dielectric-slab polarizing beam splitter (PBS) is described that generates two parallel beams of orthogonal p and s linear polarizations in reflection and functions as a diattenuator in transmission. The plane-parallel slab, which is set at Brewster's angle, is uncoated on one side and has an s-polarization antireflection coating (s-ARC) on the other side. Analytical results are presented for...

Organic (P3HT/PCBM) solar cells are coated with ZnO nanowires as antireflection coatings and show up to 36% enhancement in efficiency. The improvement is ascribed to an effective refractive index which results in Fabry-Perot absorption bands which match the polymer band-gap. The effect is particularly pronounced at high light incidence angles. Simultaneously, the coating is used as a UV-barrier...