The Effect of Using 1-Dodecanethiol as a Processing Additive on the Performances of Polymer Solar Cells

We introduce 1-Dodecanethiol (DT) to poly(3-hexylthiophene) (P3HT)/6,6-phenyl-C₆₁-butyric acid methyl ester based polymer solar cells as a processing additive. When the amount of DT is 1vol%, the device performance is best. A final power conversion efficiency of 3.1% is achieved, which is an improvement of more than 40% compared to the reference solar cell without DT. To investigate the causes of improvement of the PCE, UV-vis spectroscopy, external quantum efficiency (EQE) is measured and an AFM is used. The enhanced photovoltaic performances are discussed in terms of optical properties and the film morphology.