Anomalous photoconductivity variations of solar cell quality a-Si:H thin films induced by proton irradiation

Sato, Shinichiro; Sai, Hitoshi*; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Kondo, Michio*; Oshima, Takeshi

Photoconductivity (PC) variations of a-Si:H thin films irradiated with 0.10, 1.0 or 10 MeV protons were investigated. According to the results, the PC values of all samples once increased and after that decreased dramatically. In order to obtain the knowledge about the anomalous PC increment, time dependence of the PC value increased by 10 MeV proton irradiation was also investigated. As a result, even the PC value after 270 hours was over twice higher than that before the irradiation, though the PC values decreased with time. However, the PC value became almost equivalent to the PC before the proton irradiation by applying light-soaking. These results mean that the anomalous PC increment is metastable.