文档介绍：ZnO Pyramidal Arrays: Novel Functionality in Antire?ectionYongshu Tian,?,?Chenguo Hu,*,?Yufeng Xiong,§Buyong Wan,?Chuanhui Xia,?Xiaoshan He,?and Hong Liu|Department of Applied Physics, Chongqing UniVersity, Chongqing 400044, PR China, munication Institute, Chongqing 400035, PR China, National Center for Nanoscience and Technology,Beijing 100080, PR China, and State Key Laboratory of Crystal Materials, Shandong UniVersity,Jinan 250100, PR ChinaReceiVed: December 15, 2009; ReVised Manuscript ReceiVed: April 22, 2010We introduce a new type of ZnO array structure that can effectively suppress the re?ection of light at a rangeof wavelength from ultraviolet through visible part to the near-infrared region, with re?ectivity<%, resultingin its black color. This black ZnO posed of a random pyramidal array growing directly on Zn foilthrough a simple hydrothermal method. We have investigated the causes of antire?ection by removing thepyramid tips via scratching and ion etching on the ZnO surface. All results demonstrate that the antire?ectionnature of the black ZnO originates from the pyramidal array structure, which causes a gradient change ofrefractive index between air and . IntroductionZnO as an important functional material has been widelyinvestigated and would keep attracting attention -4Nanostructures of ZnO are one of the most splendid familiesof ,6The wurtzite structure of ZnO is unique forits noncentral symmetry and the polar electrostaticinteraction energy and distinct chemical activities of the polarsurfaces result in the formation of a wide range of nanostruc-tures, such as nanosprings,8nanorings,9nanobows,10and nano- aligned ZnO nanoarrays have a variety ofastonishing applications in electronics, optoelectronic, andelectromechanical -14It is well known thatmorphology difference of nanomaterials induces differentproperties. Very recently, She et three types of1D