Inverted tandem organic solar cells with a MoO_3/Ag/Al/Ca intermediate layer

摘要

An inverted tandem organic solar cell, consisting of two bulk heterojunction subcells with identical poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C_(61) active layer, and an intermediate layer made of ultrathin multiple metal layers of Ca/Al/Ag and metal oxide MoO_3, is reported. This' intermediate layer is of advantage in high transparency and low series resistance. Moreover, it serves as the charge recombination center effectively, and renders an exact summation of the open-circuit voltages (1.18. V) of the two subcells and a high fill factor (61.8%). The maximum power conversion efficiency obtained is 2.78% under simulated 100 mW/cm~2 [air mass (AM) 1.5G] solar irradiation, comparable to those of the two subcells.