2012/08/03 by Luca Pirro, L. Pirro, Anuj Girdhar +5 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Band gap #Condensed matter physics #Electric field #Electric potential #Electron mobility #Field-effect transistor #Formalism (music) #Graphene #Graphene research and applications #Impact ionization #Ion #Ionization #Materials science #Multiple exciton generation #Nanotechnology #Optoelectronics #Physics #Quantum and electron transport phenomena #Quantum mechanics #Semiconductor materials and devices #Transistor #Voltage #cond-mat.mes-hall
paper · pdf · doi:10.1063/1.4761995
arxiv created 2012/08/03 · openalex publication_date 2012/11/01 · arxiv updated 2015/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We develop a model for carrier generation by impact ionization in graphene, which shows that this effect is non-negligible because of the vanishing energy gap, even for carrier transport in moderate electric fields. Our theory is applied to graphene field effect transistors for which we parameterize the carrier generation rate obtained previously with the Boltzmann formalism [A. Girdhar and J. Leburton, Appl. Phys. Lett. 99, 229903 (2011)] to include it in a self-consistent scheme and compute the transistor I-V characteristics. Our model shows that the drain current exhibits an “up-kick” at high drain biases, which is consistent with recent experimental data. We also show that carrier generation affects the electric field distribution along the transistor channel, which in turn reduces the carrier velocity.