Wavelength-selective absorption enhancement in thin-film solar cells

Abstract

We present the general principle of wavelength-selective enhancement of absorption in thin-film solar cells by a periodic grating substrate. By exact numerical calculation we demonstrate that substantial short-circuit current gains are realizable in thin-film amorphous silicon (a-SiHx) solar cells. In particular, for a 0.5-μm-thick a-SiHx solar cell, optimal texturing of an Ag substrate to form a one-dimensional reflective grating can yield a 2-mA/cm2 enhancement over the flat substrate case. For a two-dimensional cross-hatched grating substrate the enhancement is estimated to be 3.5–4 mA/cm2.