Enhanced Performance and Fermi-Level Estimation of Coronene-Derived Graphene Transistors on Self-Assembled Monolayer Modified Substrates in Large Areas

Abstract

The performance of graphene field effect transistors (GFETs) strongly depends on the interface between graphene sheets and the underlying substrates. In this work, we report that an octadecyltrimethoxysilane (OTMS) SAM modified conventional SiO2/Si substrate can consistently enhance the performance of coronene-derived large-area graphene FETs. The improved transport properties in terms of boosted carrier mobility (up to 10 700 ± 300 cm2 V–1 s–1), long mean free path, nearly vanished hysteretic behavior, and remarkably low intrinsic doping level are mainly attributed to the strong suppression of interfacial charge impurity scattering and remote interfacial phonon (RIP) scattering, less adsorption of dipolar adsorbates, and the attenuated charger transfer at the interface of graphene and dielectric. The intrinsic doping levels (the Fermi energy) of graphene on OTMS-modified and bare SiO2 have been quantitatively estimated and confirmed by the Dirac points of GFETs, the Raman mapping of G-peak positions, and the surface potential maps by KPFM. The facile fabrication of a graphene device over a large area provides an unprecedented combination of high performance and low cost for the future application of all carbon-based nanoelectronics.

Theoretical study of stability and charge-transport properties of coronene molecule and some of its halogenated derivatives: A path to ambipolar organic-based materials?

“…Relying again on existing pentacene data, it is known how per-halogenation 22 tune from p-type towards n-type semiconductors concomitantly with opening of the herringbone angle 23 typical of acenelike structures. 24 Also note that coronene-derived graphene transistors have also been successfully prepared, 25 and that per-chlorocoronene has been already synthesised 26 as well as some fluoroaromatic solids, acting as lubricants, composed of small fluorocoronene rings. 27 However, this kind of substitution might affect many properties of the materials, ranging from enhanced stability upon moisture exposure to dramatic changes in solid-state morphology of the grown samples, which would need to be carefully investigated under the same technical conditions.…”

High Responsivity, Broadband, and Fast Graphene/Silicon Photodetector in Photoconductor Mode

“…Under ambient conditions, the work function of gold is around 4.8 to 4.9 eV. [ 25,26 ] By taking the intrinsic work function of graphene (≈4.56 eV) [30][31][32] into consideration, an energy band diagram is depicted in Figure 1 c. The Fermi energy of graphene should be around 0.16 to 0.26 eV. A built-in fi eld forms at the surface, which directs from silicon to graphene.…”

Quantitative Analysis of Scattering Mechanisms in Highly Crystalline CVD MoS2through a Self-Limited Growth Strategy by Interface Engineering

“…To avoid the uncertainty of tip work function, Au electrodes (≈100 nm in thickness, see Figure S1c in the Supporting Information) were used as reference, which were thick enough to screen the electrical infl uence of the underlying MoS 2 fl akes. [ 38 ] The contact potential difference (CPD) between the AFM tip and www.small-journal.com Figure 2 c,d). Thus the difference between the intrinsic Fermi levels of MoS 2 fl akes on OTMS and on bare SiO 2 can be obtained by estimating the CPDAu-MoS 2 Δ (see Figure 2 f), which is defi ned as [ 38 ] CPD CPD CPD…”

“…[ 38 ] The contact potential difference (CPD) between the AFM tip and www.small-journal.com Figure 2 c,d). Thus the difference between the intrinsic Fermi levels of MoS 2 fl akes on OTMS and on bare SiO 2 can be obtained by estimating the CPDAu-MoS 2 Δ (see Figure 2 f), which is defi ned as [ 38 ] CPD CPD CPD…”