Electron Thermionic Emission from Graphene and a Thermionic Energy Converter

By S. Liang, Lay Kee Ang. 2015

182 citations recorded by the source corpus.

In this paper, we propose a model to investigate the electron thermionic emission from a single-layer graphene (ignoring the effects of substrate) and to explore its application as the emitter of thermionic energy convertor (TIC). An analytical formula has been derived, which is a function of temperature, work function and Fermi energy level. The formula is significantly different from the traditional Richardson-Dushman (RD) law for which it is independent of mass to account for the supply function of the electrons in the graphene behaving like massless Fermion quasiparticles. By comparing with a recent experiment [Kaili Jiang et al., Nano Research 7, 553 (2014)] measuring electron thermionic emission from a suspended single layer graphene, our model predicts that the intrinsic work function of a single-layer graphene is about 4.514 eV with a Fermi energy level of 0.083 eV. For a given work function, a new scaling of $T^{3}$ is predicted, which is different from the traditional RD scaling of $T^2$. If the work function of the graphene is lowered to 2.5 to 3 eV, and the Fermi energy level is increased to 0.8 to 0.9 eV, it is possible to design a graphene cathode based TIC operating at around 900 K or lower, as compared with the metal-based cathode TIC (operating at about 1500 K). With a graphene based cathode (work function = 4.514 eV) at 900 K, and a metallic based anode (work function = 2.5 eV) like LaB$_6$ at 425 K, the efficiency of our proposed-TIC is about 45$\%$

Subfields: Civil and Structural Engineering, Materials Chemistry, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/0b52add74f1e7ebfa84ab42daed9fdd78ccc50ae

Citations in the corpus

• Space–charge limited current in nanodiodes: Ballistic, collisional, and dynamical effects (2021, unknown): “For thermionic emission vertically out from a 2D planar material, β varies from 2 to 3 where carrier scattering effects are nearly absent 173 and able to provide agreement with thermionic emission from a suspended graphene sample.”
• Hybrid graphene/silicon Schottky photodiode with intrinsic gating effect (2017, unknown): “1, 32, 33]. Our estimations are based on the assumption of the theoretical A∗. Indeed, according to the experimental evidence, this value could be several orders of magnitude higher than the real one [16,32,34]. Although the origin of a lower effective Richardson constant is still under debate [35,3”