Low cost patterning of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) films to increase organic photovoltaic device efficiency

A low-cost lithographic technique to pattern poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) films with 10 nm deep features of 700 nm periodicity is demonstrated. The use of these patterned films in $\text{poly}\left(3\text{-hexylthiophene}\right):\left[6,6\right]{\text{-phenylC}}_{61}\text{-butyric}$ acid methyl ester organic photovoltaic devices leads to an increase in short circuit current $\left(J_{\text{sc}}\right)$ , fill factor, and power conversion efficiency (PCE) with only a slight reduction in open circuit voltage. Patterning the PEDOT:PSS at $150°\text{C}$ increases $J_{\text{sc}}$ from 2.44 to $3.03\text{mA}/{\text{cm}}^2$ improving the PCE from 0.63% to 0.81% with similar increases due to patterning also being obtained at other temperatures.