PEDOT:PSS-CrO3 composite hole-transporting layer for high-performance p-i-n structure perovskite solar cells

A solution-processed hole-transporting layer for planar perovskite solar cells (PSCs) is developed by simply incorporating the CrO3 aqueous solution into the ploy(3,4-ethylene-dioxythiophene): ploystyrenesulfonate (PEDOT: PSS) aqueous dispersion. Besides the merits of high conductivity and interface modification, PEDOT:PSS-CrO3 composite films can act as a good underlayer for the growth of the crystal perovskite films. The CH3NH3PbI3-xClx film deposited on the PEDOT:PSS-CrO3 underlayer demonstrates high quality with large-scale domains and good film uniformity, which results in obvious improvement of the absorption in almost whole visible-light range. The resulting PSC device shows a power conversion efficiency (PCE) as high as 16.90%.