INFLUENCE OF SURFACE TEXTURIZATION ON THE LIGHT TRAPPING AND SPECTRAL RESPONSE OF SILICON SOLAR-CELLS

A quantitative model is presented to explain the spectral response, internal quantum efficiency, total short-circuit current, open-circuit voltage, and efficiency of high-efficiency solar cells with textured front surface and Lambertian back-surface reflector. A comparison of the textured cell characteristics is made with those of planar cells and the separate roles of the front surface reflection coefficient and internal quantum efficiency in enhancing the short-circuit current have been investigated. It is shown that in case of large diffusion lengths, almost all the contribution towards the increase of spectral response on texturization is due to the reduced reflection coefficient while for small diffusion length, there is a significant increase in internal quantum efficiency on texturization, specially in the region of higher wavelengths. However, there is a small decrease in open-circuit voltage for large diffusion lengths whereas no significant change is observed for small diffusion lengths on texturization. Nevertheless, there is a net gain in power conversion efficiency which is larger for smaller diffusion lengths.