An Efficient Triple-Tandem Polymer Solar Cell

We present an efficient triple-tandem polymer solar cell with identical poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6, 6)C₆₁ (PCBM) bulk heterojunction as the active layers and highly transparent Al (1 nm)/ MoO₃ (15 nm) as the intermediate layer. This intermediate layer is structurally smooth as characterized by atomic force microscopy. Although identical organic active layers are used to construct such triple-tandem cell, a tripled open-circuit voltage of 1.73 V and power conversion efficiency of 2.03% are obtained under simulated solar irradiation of 100 mW/cm² (AM1.5), demonstrating a viable technique for fabricating triple-tandem polymer cell with the intermediate layer of Al/MoO₃.