Towards more eco-friendly organic solar cells with PPDT2FBT:PCBM active layer devices on paper substrates

As organic photovoltaic (OPV) devices become more pervasive, ensuring that the materials synthesis, device processing and disposal of devices after their lifetime are all environmentally friendly is critical. Towards this end, we present OPV devices built using the PPDT2FBT donor polymer, which can be synthesized using the more ecofriendly direct-(hetero )arylation route; non-chlorinated o-xylene solvent, for active layer formation; and paper substrates for device fabrication. PPDT2FBT: PCBM bulk-heterojunction devices of area 16 sq. mm were built - initially on glass and then on paper substrates. An optimum efficiency of 9.49% on glass substrates was achieved with a 6 nm thick MoOx, hole transport layer. For the devices built on paper substrates, a maximum efficiency of 5.93 % was achieved.