Efficient bifacial perovskite solar cell based on a highly transparent poly(3,4-ethylenedioxythiophene) as the p-type hole-transporting material

A novel bifacial perovskite solar cell (PSC) is devised and prepared by using a highly transparent poly(3,4-ethylenedioxythiophene) (PEDOT) electrode. The PEDOT is used as the p-type hole-transporting material (HTM) due to the well matched band positions for the charge separation and transport. Moreover, the PEDOT layer can play a role of electron blocking layer at the CH3NH3PbI3/PEDOT interface to reduce the electron recombination rate because of its LUMO level is higher than that of the perovskite sensitizer. As a result, the bifacial PSC based on the PEDOT HTM yields front and rear efficiencies of 12.33% and 11.78% respectively, which are higher than those of the PSC without the PEDOT HTM (8.67% and 8.27% of the front and rear efficiencies). And the front efficiency is only decreased by 4.46% to the rear efficiency. These promising results highlight the potential application of the PEDOT in the cost-effective and transparent PSC, which could be used in the bifacial solar cell and tandem solar cell. (C) 2015 Elsevier B.V. All rights reserved.