Title

Multiple Exciton Generation in Graphene Nanostructures

Document Type

Journal Article

Role

author

Standard Number

1932-7447

Journal Title

Journal of Physical Chemistry C

Volume

114

Issue

34

First Page

14332

Last Page

14338

Publication Date

2010

Abstract

Multiple exciton generation has the promise of improving photovoltaic device efficiency. However, occurrence of this phenomenon in semiconductor nanocrystals is controversial. Using the Pariser−Parr−Pople Hamiltonian and an impact ionization mechanism, we examined over 800 finite graphene nanostructures and have identified cove-periphery hexagons, armchair-periphery hexagons, zigzag parallelograms, rectangular, and cove-periphery rectangular structures with efficient low-threshold biexciton generation. Using the experimental exciton cooling rate, we estimate that absorbed photons can generate between 1.3 and 1.8 biexcitons per absorbed photon in optimal structures. -- author supplied description

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