Enhanced near IR absorption in random, RIE-textured silicon solar cells: the role of surface profiles

摘要: We report on the role of surface profiles exhibiting comparable reflectance in random reactive ion etched textured Si solar cells. Internal quantum efficiency measurements demonstrate significant near IR absorption enhancement with peaks at /spl lambda/ sim/ 1120 nm and 1050 nm. Using Fourier analysis surfaces, we find a majority spatial structures 0.3-5-/spl mu/m range. This distribution subwavelength periodic leads to enhanced oblique coupling into through diffractive optics mechanisms. The surfaces supporting finer features create diffraction orders propagating larger angles enhancing light propagation. Random almost vertically resulting little coupling, for some structures, no absorption.