  Unique properties of lead chalcogenides have enabled multiple exciton
generation (MEG) in their nanocrystals that can be beneficial in enhancing the
efficiency of the third generation solar cells. Although the intrinsic electric
field plays an imperative role in a solar cell, its effect on the multiple
exciton generation (MEG) has been overlooked, so far. Using EOM-CCSD as a
many-body approach, we show that any electric field can affect the absorptivity
spectra of the lead chalcogenide nanocrystals (Pb4Te4, Pb4Se4, and Pb4S4). The
same electric field, however, has insignificant effects on the MEG quantum
probabilities and the thresholds in these nanocrystals. Furthermore,
simulations show that Pb4Te4, among the aforementioned nanocrystals, has the
lowest MEG threshold and the strongest absorptivity peak that is located in the
multi-excitation window, irrespective of the field strength, making it the most
suitable candidate for MEG applications. Simulations also demonstrate that an
electric field affects the MEG characteristics in the Pb4Te4 nanocrystal, in
general, less than it perturbs MEG characteristics in Pb4Se4 and Pb4S4
nanocrystals. Our results can have a great impact in designing optoelectronic
devices whose performance can be significantly influenced by MEG.
