Determination of Lifetime of Double-Layer CuPc/C60 Organic Solar Cells by Optical Electric-Field-Induced Second-Harmonic Generation Measurement

By using optical electric-field-induced second-harmonic generation measurement (EFISHG), we directly probed carrier transport processes in double-layer organic solar cells (OSCs). Results showed that excessive negative charges accumulated at the CuPc/C60 interface under photoillumination, and the accumulated charges decayed in a two-step process in dark. The EFISHG measurement is available for catching carrier process at the donor/acceptor interface of multi-layer OSCs to evaluate carrier lifetime of the cell.