Organic Photovoltaic Cells with Stable Top Metal Electrodes Modified with Polyethylenimine

摘要

Efficient organic photovoltaic cells (OPV) often contain highly reactive low-work-function calcium electron-collecting electrodes. In this work, efficient OPV are demonstrated in which calcium electrodes were avoided by depositing a thin layer of the amine-containing nonconjugated polymer, polyethylenimine (PEIE), between the photoactive organic semiconductor layer and stable metal electrodes such as aluminum, silver, or gold. Devices with structure ITO/poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PE-DOT:PSS))poly(3-hexylthiophene):indene-C_(60)-bis-adduct (P3HT:ICBA)/PEIE/Al demonstrated overall photovoltaic device performance comparable to devices containing calcium electron-collecting electrodes, ITO/PEDOT:PSS/P3HT:ICBA/Ca/Al, with open-circuit voltage of 775 ±6 mV, short-circuit current density of 9.1 ± 0.5 mA cm~(-2), fill factor of 0.65 ± 0.01, and power conversion efficiency of 4.6 ± 0.3%, averaged over 5 devices at 1 sun.