High contrast distributed Bragg reflectors based on Si:H/SiC:H PECVD multilayer structure

In this work we study the high contrast distributed Bragg reflectors (DBRs) based on plasma deposited Si:H/SiC:H films. Optical constants of these materials were measured by means of spectral ellipsometry and used in theoretical calculations of spectral transmittance and reflectance. The stacks consisted of 13 layers of the films were designed to provide stop band center at λ= 835 (DBR1) and 565 nm (DBR2). High reflectance (>90%) for DBR1 and lower value of 70% for DBR2 was measured with bandwidth Δλ=260 nm. The properties of DBR1 are of promise as back reflector in PECVD PV solar cells because of his stop band characteristics and complete compatibility with solar cell fabrication. While DBR2 structure shows worse filter properties suggesting significant effect of light absorption in Si:H layers.