Study of the effect of light irradiation on the electronic structure of organic semiconductor films

利用光电子能谱研究了光辐照对供体/受体异质结界面电子结构的影响。在光的照射下，光电子能谱的偏移与DA异质结光伏电池的光电压极性相对应。光电子能谱的偏移是由给体（受体）层的光生空穴（电子）引起的。位移值小于DA异质结光伏电池开路电压的典型值。目前的结果表明，有机光伏电池中电动势的发展与光伏电池中用于光产生电荷的半透膜的存在密切相关。

The effect of the light irradiation on the electronic structure of a donor/acceptor(DA) heterojunction interface was investigated by using the photoelectron spectroscopy. Under the light irradiation, the photoelectron spectrum was shifted corresponds to the polarity of the photovoltage of the DA heterojunction photovoltaic cell. The shift of photoelectron spectrum was caused by the photo-generated holes(electrons) in the donor(acceptor) layer. The shift value was, however, smaller than the typical value of open-circuit voltage of the DA heterojunction photovoltaic cell. The present results imply that the development of an electromotive force in an organic photovoltaic cell is closely related to a presence of semipermeable membranes for the photo-generated charges in the photovoltaic cell.