Role of electron and hole collecting buffer layers on the stability of inverted polymer: Fullerene photovoltaic devices

Systematic device performance and air stability comparison of inverted architecture P3HT:PCBM cells with six different electron collecting layers (ECL) and two hole collecting layers are presented in this study. Regardless of the ECL, we achieved an efficiency of over 3.5% and lifetime of over 1000 h. These results prove the interchangeability of different ECLs (TiOx, ZnO and PFN). Over 5000 h long air exposure revealed a secondary failure of inverted cells. Notably, devices with PEDOT:PSS/Ag/Al electrode exhibited the longest lifetime of 4000 h compared to 3000 h with MoO₃/Ag/Al.