earticle

영어

Environment-friendly methods in the semiconductor fabrication process are of high importance for sustainable development. Especially, the use of materials that are produced without complex syntheses can be an efficient strategy. For example, lignosulfonate is a chemical waste generated by a byproduct of pulp. However, this contains the ionic functional groups, which can tailor the work function of the electrode. Therefore, the use of lignosulfonate in semiconductor devices would be very promising. However, the electronic structure of a lignosulfonate film and its application in organic solar cells (OSCs) have not been reported yet. Here, we fabricated inverted OSCs using a lignosulfonate thin film. The lignosulfonate film was deposited between the poly (3-hexylthiophene -2,5-diyl) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) absorption layer and the indium tin oxide (ITO) cathode with spin coating. The thickness of the lignosulfonate film was controlled by varying the solution concentration. The current density-voltage curves of OSCs were measured upon air mass 1.5G 1 sun illumination. With the insertion of the lignosulfonate film, significantly enhanced device performance was observed. To understand the role of lignosulfonate in OSCs, the electronic structure of the lignosulfonate film on ITO was measured using X-ray photoelectron spectroscopy. Furthermore, the light-soaking effect of the lignosulfonate film was investigated with various soaking times. Through these results, we revealed that lignosulfonate can be an efficient cathode modifier in OSCs.