Organic solar cells made with recyclable cellulose substrate

Ars Technica : Organic solar cells, which use a polymer-based photoactive layer that is normally placed on top of an inorganic substrate layer, have achieved efficiencies of more than 10% in the lab. A new solar cell created by researchers from Georgia Tech and Purdue University uses an organic, cellulose substrate layer to obtain 2.7% efficiency. Although significantly less efficient, the cellulose substrate has several potential benefits, including lower cost, minimal use of toxic chemicals, and recyclability. And recent research suggests that if an organic solar cell can reach 5% efficiency and a lifetime of 5 years, it would be commercially viable. The researchers created the organic substrate by breaking down softwood pulp in sulfuric acid, then cleaning, drying, and purifying the material until they had a thin, transparent layer of cellulose nanocrystals. Once the cell is no longer usable, both the substrate and photoactive layers can be dissolved away, recycled, or reused. The researchers’ immediate goal is to increase the new cell’s efficiency to more than 10% before looking into its commercial viability.