Efficient organic Schottky junction solar cells with a platinum chloride-treated PEDOT:PSS interfacial layer

We demonstrate highly efficient organic-based Schottky junction solar cells (OSJSCs) obtained by poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) modification with solution-processed platinum chloride (PtCl₄) treatment. The effect of PtCl₄ on PEDOT:PSS properties and device performances of solar cells was investigated. Kelvin probe and 4-point probe studies demonstrated that PtCl₄ decreased the PEDOT:PSS sheet-resistance and increased the PEDOT:PSS work-function, thereby inducing an improved built-in potential and interface resistance. As a result, with the aid of the PtCl₄ treatment, the Schottky junction device had a high power conversion efficiency of 3%, which was more than 20% higher than the reference OSJSCs with no PtCl₄, indicating that PtCl₄ can be a promising PEDOT:PSS modifier for raising the cell-performances of Schottky-junction based organic solar cells. (paper)