Investigators

Kelly Gaffney, SLAC; Yi Cui and Mike McGehee, Materials Science & Engineering, Stanford University

Objective

This exploratory project aims at implementing a novel time-resolved spectroscopic diagnostic technique to validate recent experimental estimates of the efficiency of multiple exciton generation (MEG) in semiconductor nanoparticles following the absorption of a single high-energy photon. As opposed to traditional transient absorption measurements performed at the band gap energy, the proposed experiment uses the excited-state absorption as a signature of multiple exciton generation. This approach avoids using questionable assumptions, such as the weak interaction between multiple excitons within a quantum dot, in interpreting the results.

Progress Report

• 2010 Progress Report (PDF)

Publications

• Ji, Minbiao, J., S. Park, S. T. Connor, T. Mokari, Y. Cui, and K. J. Gaffney. “Efficient multiple exciton generation observed in colloidal PbSe quantum dots with temporally and pectrally resolved intraband excitation.” Nano Letters, 9 (3), 1217-1222, (2009).
• S. T. Connor, C.-M. Hsu, B.Weil, Y. Cui, Mechanistic Studies of CuInS2 Nanocrystal Growth, J. Am. Chem. Soc. (in press 2009).
• Goris, L., R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo. Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis. Journal of electronic materials 38, no. 4 (2009): 586-595.
• Dewan, Rahul, Marko Marinkovic, Rodrigo Noriega, Sujay Phadke, Alberto Salleo, and Dietmar Knipp. Light trapping in thin-film silicon solar cells with submicron surface texture. Optics Express 17, no. 25 (2009): 23058-23065.

Presentations