ABSTRACT
In this study, we investigated hybrid bulk heterojunction organic solar cells containing ZnO nanoparticles blended with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) and having poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) or N,N-dimethylformamide (DMF)-modulated PEDOT:PSS buffer layers. The reference cell, which had a P3HT:PCBM active layer sandwiched between ITO\PEDOT:PSS and LiF\Al electrodes, exhibited an efficiency of 1.55%. The ZnO nanoparticle-doped active layer (ITO\PEDOT:PSS(DMF) \ZnO:P3HT:PCBM\LiF\Al) exhibited a higher efficiency of 3.39% due to the modulated PEDOT:PSS buffer layer with low resistivity and the hybrid active layer containing ZnO nanoparticles. Here, we demonstrate that the low resistivity of the PEDOT:PSS layer can improve the Jsc value of hybrid solar cells, and ZnO nanoparticles can enhance the Voc value of organic solar cells.
ABSTRACT
This study analyzed the properties of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) thin-films prepared by spin-coating solutions made with the polar solvents methanol, acetone, or N,N-dimethylformamide (DMF). A characteristic analysis was carried out for poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C(61)-butyric acid methyl ester (PCBM)-based organic solar cells (OSCs) having these modified PEDOT:PSS thin-films as the hole transport layer. The resistivity of the PEDOT:PSS thin-film obtained from the DMF solution was 4.89 × 10(-3) Ω·cm with a roughness of 3.23 × 10° nm, compared to 3.51 × 10(-1) Ω·cm and 7.72 × 10(-1) nm for a pristine PEDOT:PSS thin-film. The dipole moment increase of the solvent led to the decreased resistivity and the increased roughness and transparency of PEDOT:PSS thin-films on the structural arrangement of the polymers. Highly efficient OSCs with a power conversion efficiency of 3.47% were obtained when DMF-treated PEDOT:PSS thin-film was used as the hole transport layer.
