Lithium salts as “redox active” p-type dopants for organic semiconductors and their impact in solid-state dye-sensitized solar cells

Abate, A. et al. (2013) Lithium salts as “redox active” p-type dopants for organic semiconductors and their impact in solid-state dye-sensitized solar cells. Physical Chemistry Chemical Physics, 15(7), pp. 2572-2579. (doi: 10.1039/C2CP44397J) (PMID:23310946)

Abstract

Lithium salts have been shown to dramatically increase the conductivity in a broad range of polymeric and small molecule organic semiconductors (OSs). Here we demonstrate and identify the mechanism by which Li+ p-dopes OSs in the presence of oxygen. After we established the lithium doping mechanism, we re-evaluate the role of lithium bis(trifluoromethylsulfonyl)-imide (Li-TFSI) in 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-Spirobifluorene (Spiro-OMeTAD) based solid-state dye-sensitized solar cells (ss-DSSCs). The doping mechanism consumes Li+ during the device operation, which poses a problem, since the lithium salt is required at the dye-sensitized heterojunction to enhance charge generation. This compromise highlights that new additives are required to maximize the performance and the long-term stability of ss-DSSCs.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Docampo, Dr Pablo
• Authors: Abate, A., Leijtens, T., Pathak, S., Teuscher, J., Avolio, R., Errico, M. E., Kirkpatrik, J., Ball, J. M., Docampo, P., McPherson, I., and Snaith, H. J.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Physical Chemistry Chemical Physics
• Publisher: Royal Society of Chemistry
• ISSN: 1463-9076
• ISSN (Online): 1463-9084
• Published Online: 12 December 2012