Kelly Gaffney, SLAC; Yi Cui and Mike McGehee, Materials Science & Engineering, Stanford University
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.
- 2010 Progress Report (PDF)
- 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, doi:10.1021/nl900103f (2009).