Wire textured, multi-crystalline Si solar cells created using self-assembled masks.

We have developed an inexpensive and scalable method to create wire textures on multi-crystalline Si solar cell surfaces for enhanced light trapping. The wires are created by reactive ion etching, using a monolayer high self-assembled array of polymer microspheres as an etch mask. Chemical functionalization of the microspheres and the Si surface allows the mask to be assembled by simple dispensing, without spin or squeegee based techniques. Surface reflectivities of the resulting wire textured multi-crystalline solar cells were comparable to that of KOH etched single crystal Si (100). Electrically, the solar cells exhibited a 20% gain in the short circuit current compared to planar multicrystalline Si control devices, and a relative increase of 7-16% in the "pseudo" efficiencies when the series resistance contributions are extracted out.