Impact Ionization and Carrier Multiplication in Graphene

Abstract

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 parametrize 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.

References in corpus (4)

• Graphene field-effect-transistors with high on/off current ratio and large transport band gap at room temperature
• Electron-Hole Generation and Recombination Rates for Coulomb Scattering in Graphene
• Modeling of the Output and Transfer Characteristics of Graphene Field-Effect Transistors
• Soft Carrier Multiplications by Hot Electrons in Graphene

Cited by in corpus (9)

• Nonequilibrium plasmons with gain in graphene
• Impact of doping on the carrier dynamics in graphene
• Short channel effects in graphene-based field effect transistors targeting radio-frequency applications
• Graphene as Gain Medium for Broadband Lasers
• Theory of low power ultra-broadband terahertz sideband generation in bi-layer graphene
• Scaling of graphene field-effect transistors supported on hexagonal boron nitride: radio-frequency stability as a limiting factor
• Collinear scattering of photoexcited carriers in graphene
• Impact ionization induced by terahertz radiation in HgTe quantum wells of critical thickness
• Spatially controlled electrostatic doping in graphene p-i-n junction for hybrid silicon photodiode