How to Make Polymer Solar Cells

By Tricia Lobo
Scientists hope that polymer solar cells, unlike today's solar panels, can one day be so simple as to be simply painted onto rooftops as a source of energy.
photovoltaik image by Otmar Smit from

Polymer solar cells are flexible solar cells consisting of polymers that use sunlight to produce energy. They offer many advantages over traditional solar cells. They are relatively inexpensive to produce, lightweight, disposable, customizable at the molecular level, and more environmentally sustainable. Polymer solar cells employ electron donor regions (polymers) and electron acceptor regions (fullerenes). Electrons in polymer cells get excited by absorbed light of different wavelengths and are acquired by the acceptor region. Electrons are separated in the electric field, interact with the cathode (positively charged) part of the solar cell, and are collected as a source of usable energy.

Combine a polymer such as light-sensitive poly(3-hexylthiophene) and a fullerene derivative like (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) (1:1, w/w) by dissolving both in an organic solvent such as 1,2,4-trichlorobenzene.

Coat the combined polymer-fullerene layer onto a patterned monolayer, a surface with a pattern etched into it. The pattern will induce phase separation between the polymer and fullerenes, keeping them apart and distinct from one another and leading to the most efficient energy transfers possible.

Allow the active layer to spontaneously dry, inducing phase separation.

Heat the panel in an oven at 110 degrees Celsius for 15 minutes to remove residue organic solvent.

Deposit aluminum and calcium onto the polymer portion, to form the cathode.

About the Author

Tricia Lobo has been writing since 2006. Her biomedical engineering research, "Biocompatible and pH sensitive PLGA encapsulated MnO nanocrystals for molecular and cellular MRI," was accepted in 2010 for publication in the journal "Nanoletters." Lobo earned her Bachelor of Science in biomedical engineering, with distinction, from Yale in 2010.