Advanced Broadband Antireflection Coatings Based on Cellulose Microfiber Paper

In order to absorb a significant fraction of the incident sunlight, a solar cell must incorporate light management techniques, including high-quality antireflection coatings. Such coatings are typically produced via high-temperature deposition methods that are costly. Here, we present a new technique based on light scattering within a transparent paper that is placed on top of a solar cell. The optical and electronic responses of both Si and GaAs solar cells are tested with these coatings, and a broadband angle-insensitive response is achieved. A comparison between textured and untextured solar cells is also made, and the power conversion efficiency is improved for untextured surfaces, while the increased path length within the paper resulting from textured cells increases absorption within the paper. The process is simple and inexpensive, and the paper coatings are made from a recyclable material, leading to less environmental impact.