Balanced carrier transport in organic solar cells using implanted indium-tin-oxide nano-columns

In this paper, we present evidence of balanced electron and hole transport in polymer-fullerene based solar cells by means of embedded indium-tin-oxide nano-electrodes. Enabled by a controllable electrochemical deposition, the individual nano-electrodes are uniformly enclosed by a poly(3,4-ethylenedioxythiophene) hole-conducting layer, allowing a relatively short route for holes to reach the anode and hence increasing the effective hole mobility. Consequently, the power conversion efficiency and photogenerated current are maximized with a deposition condition of 50 μC, where the ratio of the electron to hole mobility is nearly unity.