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arXiv · 1209.4346

Photo-excited Carrier Dynamics and Impact Excitation Cascade in Graphene

Justin C. W. Song·Klaas J. Tielrooij·Frank H. L. Koppens·Leonid S. Levitov
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Abstract

Photo-excitation in solids can trigger a cascade in which multiple particle-hole excitations are generated. We analyze the carrier multiplication cascade of impact excitation processes in graphene and show that the number of pair excitations has a strong dependence on doping, which makes carrier multiplication gate-tunable. We also predict that the number of excited pairs as well as the characteristic time of the cascade scale linearly with photo-excitation energy. These dependences, as well as sharply peaked angular distribution of pair excitations, provide clear experimental signatures of carrier multiplication.

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Justin C. W. Song, Klaas J. Tielrooij, Frank H. L. Koppens, Leonid S. Levitov. 2012-09-19. Photo-excited Carrier Dynamics and Impact Excitation Cascade in Graphene. https://doi.org/10.1103/physrevb.87.155429

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