Engineering an interfacial interaction to assist transfer printing of active layers for curved organic solar cells

Transfer printing is a powerful technique to deposit films on surfaces that are difficult to fabricate by traditional coating methods (spin coating, inkjet printing). Adhesion tuning between the transferred film and the target surface is critical for successful transfer of the film. Typically, the transfer printing relies on Van der Waals force at the interface. In this work, we engineered an interfacial interaction to assist transfer printing of organic active layers onto the PEI-Zn (electron-transporting layer) by introducing a layer of poly(sodium-4-styrene sulfonate) (PSSNa). The adhesion increases between the active layer and PEI-Zn surface with their contact. Water between the two layers is spontaneously repelled and improves the transfer of active layer onto the PEI-Zn surface. The technique enables the direct fabrication of organic solar cells on curved surfaces. Organic solar cells on a curved vial with power conversion efficiency of 10.8% was demonstrated.