Tuning the electrical and morphological characteristics of PEDOT:PSS filmsthrough mixed cosolvent addition and performance of their polymer solar cells

This work aimed to reveal the influence of premixed cosolvent addition to low conductive PEDOT:PSS solution and how the optimized thin film conductivity develops. PEDOT:PSS thin films were obtained by addition of EG and MeOH cosolvent mixture (8, 10, and 15 v/v.%) and the morphological, electrical, optical, and bandgap properties of the films obtained were characterized by different techniques. The addition of mixed cosolvent can effectively control the grain size distribution and thus the conductivity. The optical characterization results revealed that the bandgap decreased with increasing volume of mixed cosolvent. The conductivity characteristics showed that the addition of 10% v/v.% EG-MeOH blend to low conductive PEDOT:PSS solution is optimal. Polymer solar cells (PSCs) were produced with a configuration of ITO/PEDOT:PSS/P3HT:PCBM/Al, which is one of the most common configurations examined. The highest efficiency of 2.7% was achieved, which resulted in a 20% enhancement (2.2%) compared to the control device. \end{abstract}