Reflectance of Sub-Wavelength Structure on Silicon Nitride for Solar Cell Application

Abstract

In this study, reflection properties of sub-wavelength structures (SWS) on silicon nitride (Si(3)N(4)) antireflective coatings are investigated. Numerical calculation of SWS reflection based on a rigorous coupled-wave approach is conducted and compared with the measurement of fabricated samples. We compare the results of single- and double-layer-antireflection (SLAR and DLAR) coatings with SWS on Si(3)N(4), taking into account average residual reflectivity over a range of wavelengths, where the solar efficiency is further estimated. A low average residual reflectivity of 9.56% could be obtained for a Si(3)N(4) SWS height and non-etched layer of 140 nm and 60 nm respectively, which will be less than 80 nm Si(3)N(4) SLAR (similar to 15%) and almost the same as that of a DLAR with 60 nm Si(3)N(4) and 70 nm magnesium fluoride (similar to 10%).