Improvement in the photoelectrochemical responses of PCBM/TiO₂ electrode by electron irradiation

The photoelectrochemical (PEC) responses of electron-irradiated [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/TiO₂ electrodes were evaluated in a PEC cell. By coating PCBM on TiO₂ nanoparticle film, the light absorption of PCBM/TiO₂ electrode has expanded to the visible light region and improved the PEC responses compared to bare TiO₂ electrode. The PEC responses were further improved by irradiating an electron beam on PCBM/TiO₂ electrodes. Compared to non-irradiated PCBM/TiO₂ electrodes, electron irradiation increased the photocurrent density and the open-circuit potential of PEC cells by approximately 90% and approximately 36%, respectively at an optimum electron irradiation condition. The PEC responses are carefully evaluated correlating with the optical and electronic properties of electron-irradiated PCBM/TiO₂ electrodes.