Flexible silver grid/PEDOT:PSS hybrid electrodes for large area inverted polymer solar cells

Bulk-heterojunction (BHJ) organic solar cell (OSC) has become a major thrust in solar energy research. It is highly critical to fabricate large-area high-efficiency OSCs in order to maximize the fraction of active area and hence their practical application. In this paper, we have fabricated a promising hybrid transparent electrode consisting of high resolution embedded silver grid (Ag-grid) in hybridization with high conductance poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (PH1000), which gives both high transparency and low sheet resistance. We further demonstrate its application in large-area high efficiency OSCs. By carefully tuning the properties of the Ag-grid based hybrid electrodes, the sheet resistance is further reduced to as low as 1.2 Omega sq(-1). Inverted OSCs with device area of 1.21 cm(2) exhibited a record PCE of 3.36% for poly(3-hexylthiophene):[6,6]-phenyl-C-61 butyric acid methyl ester (P3HT:PC61BM) blend film as the active layer; and the PCE of PTB7:PC71BM devices reached 5.85%. To the best of our knowledge, the PCE of 5.85% is the highest in large-area flexible OSCs (>1 cm(2)) till date. (C) 2014 Elsevier Ltd. All rights reserved.