Enhanced diffuse reflection of light into the air using silver coating on periodically textured 430BA stainless steel substrate

The total reflection (TR) rate and the diffuse reflection (DR) rate of a textured substrate are important indexes when increasing the light trapping efficiency of a solar cell. In this study, we found that the smaller the interval or the larger the diameter of a concave periodically textured 430BA stainless steel (430BA SS) substrate the more the DR rate of light was increased. In addition, a 300 nm thick Ag film was deposited on the surface of the periodically textured 430BA SS substrates by e-beam evaporation. Experimental results showed that the DR rate of Ag film coated/textured 430BA SS substrates increased 2-fold and 14-fold, compared with textured 430BA SS and raw 430BA SS substrates, respectively. Moreover, the TR rate increased to more than 90% for all of the Ag film coated/textured 430BA SS substrates. It is our belief that the increase in the TR and DR rates was due to the high reflectance of the thick and continuous Ag film coating on a textured 430BA SS substrate.