Analysis of Interfacial Charging Process in Pentacene/C60/Bathocuproine Triple-Layer Organic Solar Cells Using a Maxwell--Wagner Model

Using the Maxwell--Wagner model, we analyzed the interfacial charging of triple-layer organic solar cells (OSCs). Results showed that the charging processes at the two interfaces depend on each other. The electric-field-induced second-harmonic generation (EFISHG) measurements applying external voltage pulses supported the conclusion. On the other hand, the EFISHG measurements using closed circuits with various external resistances clarified the contribution of interfacial charging to the fill-factor of the OSCs. The dielectric nature of the triple layer of the OSCs governs the working mechanism.