Enhancement of organic solar cell efficiency by patterning the PEDOT: PSS hole transport layer using nanoimprint lithography

In order to improve the conversion efficiency of organic photovoltaic (OPV) cells, nano-patterned poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS) was used as a hole transfer layer (HTL). Using nanoimprint lithography, a process that is easily applied to large-area substrates, a spherical array of PEDOT: PSS droplets was formed. The effect of the PEDOT: PSS nanostructure was characterized by optical and electrical measurements. Because the hemispherical array of PEDOT: PSS scatters light efficiently, absorption of the incident light increases when the nanostructured layer is employed. The conversion efficiency of the nano-patterned OPV cells is 25% larger than that of non-patterned OPV cells, due to the increase in short-circuit current (J(sc)). (C) 2013 Elsevier B.V. All rights reserved.