CHEMICAL CAPACITANCE IN ORGANIC SOLAR CELLS AND ABNORMAL LARGE SPECTRAL RESPONSE OF DEGRADED ORGANIC SOLAR CELLS

摘要

Chemical capacitance is the capability of a system to release or accept additional charges on a given perturbation of its chemical potential. The concept of chemical capacitance is introduced in this study to model the ac response of organic solar cells, a nanoscale system in which chemical capacitance plays more important role than electrostatic capacitance. It shows that the increase of chemical capacitance in organic solar cells after degradation is mainly due to the deep electron traps formed in the acceptor. It is the deep electron traps that cause the abnormal large spectral response for degraded organic solar cells.