  The ability to absorb light is indispensable for high efficient solar power
generation. This places conflicting requirements on the structure of a solar
cell: On one hand, it needs to have thick active layers to absorb more of the
available sunlight while on the other it needs thinner ones for better charge
transport. This dilemma stands in the way of any semiconductor from ever
achieving its full potential as a solar cell material. Recently, external
light-traps have emerged as a cost-effective solution for this dilemma by being
able to decouple the optics from the electronic aspects of the power-generating
process in the cell. In this paper, we study the effectiveness of external
light-traps with diffusive inner reflecting walls. Results indicate that given
the correct design, external light-traps may present a genuine opportunity for
high-efficiency cost-effective solar power production.
