22 February 2012 Multiple exciton generation in PbSe nanorods
Author Affiliations +
While multiple exciton generation (MEG) is known to occur more efficiently in semiconductor nanocrystals than in the bulk, the required energy threshold prevents visible photons from being utilized. We report two-color pump-probe measurements demonstrating a two-fold increase in the MEG efficiency of solution samples of PbSe quasi onedimensional nanorods over zero-dimensional nanocrystals to a value of 0.78, where 1 is the largest efficiency possible. This improvement is accompanied by a reduction of the MEG threshold energy to 2.28Eg, which allows visible photons to participate in MEG. This approaches the theoretical limit for the threshold energy of 2Eg imposed by energy conservation. Detailed balance calculations show that, unlike nanocrystals, photovoltaic cells based on PbSe nanorods can use MEG to improve power conversion efficiencies, particularly when used in conjunction with solar concentrators.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Paul D. Cunningham, Paul D. Cunningham, Janice E. Boercker, Janice E. Boercker, Edward E. Foos, Edward E. Foos, Matthew P. Lumb, Matthew P. Lumb, Anthony R. Smith, Anthony R. Smith, Joseph G. Tischler, Joseph G. Tischler, Joseph S. Melinger, Joseph S. Melinger, } "Multiple exciton generation in PbSe nanorods", Proc. SPIE 8256, Physics, Simulation, and Photonic Engineering of Photovoltaic Devices, 825610 (22 February 2012); doi: 10.1117/12.908939; https://doi.org/10.1117/12.908939

Back to Top