Enhanced Open-Circuit Voltage in Tandem Polymer Solar Cell

We present an efficient tandem polymer organic solar cell (OSC), consisting of the P3HT:PCBM blend as the active layer, in which the bottom and top cells are connected optically and electrically by an Al and MoO
₃
intermediate layer. Such an intermediate layer has high transparency and can implement the connection of the bottom and top cells in series. The main absorption range of the active layer can be made full use of and then the summation (1.19 V) of the open-circuit voltages of individual cells was obtained. With the short-circuit current density of (3.53 mA/cm
²
), a power conversion efficiency (PCE) of 2.07% was achieved under 100 mW/cm
²
illumination, which is comparable to those of the individual cells.