Contact Doping For Organic Photovoltaics

Open Access
Author:
Woltermann, Megumi K
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Enrique Daniel Gomez, Thesis Supervisor
  • Wayne Roger Curtis, Honors Advisor
Keywords:
  • polymer solar cells
  • organic photovoltaic
  • OPV
  • SPS
  • dopant layer
Abstract:
To increase efficiency of polymer solar cells, the use of a dopant layer has been utilized. The dopant layer is the interface layer between the ITO (indium tin oxide) and active polymer layer which helps to increase contact. Currently, PEDOT:PSS is the most widely used dopant layer, but it has inherent issues. As a replacement to PEDOT:PSS, sulfonated polyphenylsulfone was explored by comparing the maximum efficiency of cells with different concentrations and levels of sulfonation. The active layer consisted of the donor polymer Poly(3-hexylthiophene) (P3HT) and the acceptor polymer indene C-60 (ICBA). After testing, the average maximum efficiency of no dopant layer was found to be 1.15%; PEDOT:PSS showed an average maximum efficiency of 2.51%; the best sulfonated dopant layer was 0.15 mg/mL with a sulfonation level of 2.33 which produced an average maximum efficiency of 2.96%. The trend of the curve showed that a higher sulfonation level and a lower concentration lead to a higher maximum efficiency. However, low sulfonation levels showed to have a negative effects on the cell and cause the efficiency of the cell to be well below the no dopant layer cell. Based on these results, sulfonated polyphenylsulfone at certain sulfonation levels show promise as a replacement for PEDOT:PSS as a dopant layer.