Researchers Create Efficient, Recyclable Solar Cells from Trees

Researchers from Georgia Institute of Technology‘s Center for Organic Photonics and Electronics (COPE), in collaboration with Purdue University have unveiled a new efficient, recyclable organic solar cell made from trees—or, more specifically, from a substrate that can be sourced not only from trees but from other plants as well. These efficient polymer solar cells are then fabricated on cellulose nanocrystal (CNC) substrates to create a more sustainable solar cell that can be quickly recycled in room-temperature water.

While this is far from the first organic solar cell to be developed, it is believed to be the first that is truly recyclable, and potentially sustainable. To date organic solar cells have, as Georgia Tech explains, largely been fabricated on glass or plastic, while others have used petroleum substrates. Professor Bernard Kippelen of the Georgia Institute of Technology led the study. Describing the research, he emphasized the importance of the team’s work: “organic solar cells must be recyclable. Otherwise we are simply solving one problem, less dependence on fossil fuels, while creating another, a technology that produces energy from renewable sources but is not disposable at the end of its lifecycle.”
The CNC substrate onto which the solar cells are fabricated are “optically transparent (like a leaf) which lets light pass through before it’s absorbed by a very thin layer of an organic semiconductor,” explains Forbes. While the current conversion efficiency rate for the tree-based solar cells might appear underwhelming, 2.7 percent, the team describe it as “unprecedented” for “cells on substrates derived from renewable raw materials.” With a provisional patent filed, the team at COPE plan to next work on reaching “power conversion efficiency over 10 percent, levels similar to solar cells fabricated on glass or petroleum-based substrates.”