Abstract
A Korean team fabricated a novel metamaterial with an index of refraction of 38.6 which is considered the most extreme positive value. In this paper, we employ the new metamaterial to construct a binary photonic crystal having the structure air/(metamaterial/SiO2)(N)/Si. The binary photonic crystal is employed as a back reflector of a thin-film silicon solar cell. The proposed back reflector has a very thin thickness of about 312 nm. It is found that the omnidirectional region for which we have 0% transmittivity for all incident angles and for simultaneously TE and TM modes is 341.8 nm in the visible region whereas it is only 155.1 nm for a structure consisting of (Si/SiO2)(N). We believe that we have a perfect back reflector with three significant properties: 1- it has a very wide bandwidth, 2- the bandwidth is in the visible range of the solar spectrum, and 3- it has a thin thickness. In addition to a back reflector, the proposed structure can be used as a wide band-stop filter.