Fabrication of textured silicon solar cell using microlens as anti-reflection layer

This paper presents facile, reproducible soft-lithographic technique for fabricating textured crystalline silicon solar cell with hexagonally close-packed hemispherical arrays using ordered polymeric microspheres. Close-packed monolayers of polymer microspheres were deposited on flat cleaned glass substrate using spin-casting technique. The relief structure of highly ordered microspheres successfully generated their negative replica of elastomers. Hemispherical microlens arrays were molded by dispensing and curing liquid ultraviolet-curable photopolymers into the negative replica on crystalline silicon solar cell module. Sub-micrometer scaled microlens with uniform, cleaned surface morphology were easily reproduced by using the prepared molds, without multi-step engineering processes. The microlens-coated crystalline silicon solar cell showed additional increment of 1% in solar cell efficiency, compared to that of SiN_x anti-reflection coated one, as well as remarkable decrease of reflectance in SiNx-uncoated solar cell.