Efficient Light Absorption with Integrated Nanopillar/Nanowell Arrays for ThreeDimensional Thin-Film Photovoltaic Applications

fficient light absorption is crucial for enhancing the performance of thin-film photovoltaic (PV) devices, which requires both broadband antireflection coat-ings and efficient light trapping techniques. Properly engineered three-dimensional (3-D) photonicnanostructures havedemonstrated highly promising capability of harvesting sunlight over a broad range of wavelengths and incident angles.16 In particular, arrays of a variety of 3-D nanostructures, such as nanowires,710 nanopillars (NPLs),11,12 nano-wells (NWLs),1,13,14 nanocones,3,4,15 nano-pyramids,1618 nanospheres,1921 and so forth, have been extensively studied for ligh