One-Dimensional Photonic Crystal Reflector using Silicon-rich Silicon Nitride and Silicon Oxynitride Multilayers for Solar Cells

Light trapping forms an important aspect of solar cells to increase the short circuit current density, which has a direct impact on the efficiency of the solar cell. In this paper we have used a one-dimensional photonic crystal which acts as a Bragg reflector. The dielectric photonic crystal consists of 6 bilayers of silicon nitride and silicon oxynitride deposited at a low temperature of 200 degrees C using radio frequency plasma-enhanced chemical vapor deposition. The deposition conditions of the materials used and the characterization by FTIR, XPS, Raman spectroscopy and XRD are presented. Finall, y the application of this material to make a near-100% broadband reflector in the wavelength range of 800 to 1200 nm using 70 nm silicon nitride and 140 nm silicon oxynitride stacks has been demonstrated.