PHOTOCARRIER DYNAMICS IN C-60 - STUDIES OF TRANSIENT PHOTOCONDUCTIVITY AND TRANSIENT PHOTOINDUCED ABSORPTION

The intrinsic dynamics of photoexcited carriers in oxygen-free C-60 fi lm and their remarkable evolution as the film is exposed to oxygen are revealed by transient photoconductivity (PC) and transient photoinduc ed absorption (PA) measurements at various temperatures, light intensi ties and photon energies. These studies reveal the carrier transport a nd carrier recombination mechanisms, and provide an estimate for the i nitial mobility in pristine C-60 film; these measurements also demonst rate that exposure C-60 film to oxygen creates deep traps that localiz e the photocarriers and effectively quenches the long-lived multiple t rapping transport mechanism.