A joint research effort between the Forest Service's Forest Products Laboratory, Georgia Institute of Technology, and Purdue University has developed efficient, reclyclable solar cells using natural substrates. The cellulose nanocrystal (CNC) substrates on which the solar cells are fabricated are optically transparent, enabling light to pass through them before being absorbed by a very thin layer of an organic semiconductor. The low surface roughness of the CNC films is critical for the thin polymer solar cells to work efficiently. During the recycling process, the solar cells are simply immersed in water at room temperature. Within only minutes, the CNC substrate dissolves and the solar cell can be separated easily into its major components.