 PCBM is a fullerene derivative of the C60 buckyball that was first synthesized in the 1990s.It is an electron acceptor material and is often used in organic solar cells (plastic solar cells) or flexible electronics in conjunction with electron donor materials such as P3HT or other conductive polymers.It is a more practical choice for an electron acceptor when compared with fullerenes because of its solubility in chlorobenzene.