| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing an expanded carbon fiber capable of effectively utilizing visual light, exhibiting an excellent photoinduced charge separating effect, and applicable for a photoelectric conversion layer or the like of a solar cell. <P>SOLUTION: The expanded carbon fiber is prepared by preparing an intercalation compound from a raw material carbon fiber, and then subjecting the intercalation compound to a heat treatment. The amount of acidic functional group and ratio of carboxyl group to the total acidic functional group on the surface of the expanded carbon fiber can be increased by subjecting the expanded carbon fiber to a surface oxidizing treatment. The amount of the ratio of the carboxyl group to the total acidic group is set at least 6%, preferably 6% or more and 83% or less. The expanded carbon fiber absorbs lights of substantially whole wave length since it exhibits an excellent photoinduced charge separating effect by irradiation with light and at the same time develops a black color, and therefore, is suitably used as the photoelectric conversion layer of the solar cell. <P>COPYRIGHT: (C)2010,JPO&INPIT |
