Improved Performance of Polymer Solar Cells Featuring One-Dimensional PEDOT Nanorods in a Modified Buffer Layer

Abstract

This paper describes the use of one-dimensional (1D) poly(3,4-ethylenedioxythiophene) nanorod (n-PEDOT) and modified poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films as anode buffer layers in polymer photovoltaic cells based on poly(3-hexylthiophene):[6,6]-phenyl--butyric acid methyl ester. We employed high-speed vibrational milling to disperse the n-PEDOTs into an aqueous PSS medium. Raman spectroscopy measurements revealed quinoid-dominated structures for these aqueous-soluble n-PEDOT:PSS materials. The presence of the 1D n-PEDOTs in the buffer layer improved the photovoltaic performance of the polymer solar cell relative to that of the system prepared using the unmodified PEDOT:PSS . This enhancement was accompanied by an increase in the values of (from ) and the fill factor (from 0.58 to 0.64). The conductivity and polarity of the n-PEDOT–modified buffer layer increased upon increasing the content of n-PEDOT, resulting in increases of the short-circuit current, open-circuit voltage, and power conversion efficiency of the polymer solar cell incorporating the 1D n-PEDOTs.