Production of large-area polymer solar cells by industrial silk screen printing, lifetime considerations and lamination with polyethyleneterephthalate

Abstract The possibility of making large area (100 cm 2 ) polymer solar cells based on the conjugated polymer poly 1,4-(2-methoxy-5-ethylhexyloxy)phenylenevinylene (MEH-PPV) was demonstrated. Devices were prepared by etching an electrode pattern on ITO covered polyethyleneterephthalate (PET) substrates. A pattern of conducting silver epoxy allowing for electrical contacts to the device was silk screen printed and hardened. Subsequently a pattern of MEH-PPV was silk screen printed in registry with the ITO electrode pattern on top of the substrate. Final evaporation of an aluminum electrode or sublimation of a Buckminsterfullerene (C 60 ) layer followed by an aluminum electrode completed the device. The typical efficiency of the prototype devices consisting of three solar cells in series were 0.0046% (under AM1.5 conditions) with open-circuit voltages ( V oc ) of 0.73 V and short-circuit currents ( I sc ) of 20 μA cm −2 . The half-life based on I sc in air for the devices were 63 h. The cells were laminated in a 125 μm PET encasement. Lamination had a negative effect on the lifetime.We demonstrate the feasibility of industrial production of large area solar cells (1 m 2 ) by silk screen printing and envisage the possibility of production volumes 10000 m 2 h −1 at a cost that is on the order of 100 times lower than that of the established monocrystalline silicon solar cells in terms of materials cost.