Photodegradation of the electronic structure of PCBM and C60 films in air

The photodegradation in air of thin-films of PCBM and C60 is studied by NEXAFS and photoemission spectroscopies. After exposure to simulated solar light or to conventional lab lighting, the electronic fingerprint of the fullerenes is completely altered, indicating degradation of the pi-conjugated system in air. These results strengthen the need for controlled processing conditions of fullerene-based films.115