Hydrogenated monolayer graphene with reversible and tunable wide band gap and its field-effect transistor

Abstract

Graphene is currently at the forefront of cutting-edge science and technology due to exceptional electronic, optical, mechanical, and thermal properties. However, the absence of a sizeable band gap in graphene has been a major obstacle for application. To open and control a band gap in functionalized graphene, several gapping strategies have been developed. In particular, hydrogen plasma treatment has triggered a great scientific interest, because it has been known to be an efficient way to modify the surface of single-layered graphene and to apply for standard wafer-scale fabrication. Here we show a monolayer chemical-vapour-deposited graphene hydrogenated by indirect hydrogen plasma without structural defect and we demonstrate that a band gap can be tuned as wide as 3.9 eV by varying hydrogen coverage. We also show a hydrogenated graphene field-effect transistor, showing that on/off ratio changes over three orders of magnitude at room temperature.

Tuning electronic and optical properties of free-standing Sn2Bi monolayer stabilized by hydrogenation

“…To stabilize the Sn2Bi free-standing monolayer, it should be hydrogenated. Hydrogen plasma treatment is a known method for modification of the surface of graphene monolayer [70]. In this method, first, the hydrogen plasma is generated in a separate gun with a microwave power of 180W at 2.5 GHz.…”

“…In this method, first, the hydrogen plasma is generated in a separate gun with a microwave power of 180W at 2.5 GHz. Then, the prepared monolayer by CVD is placed 10 cm away from the end of the gun while the flow rate of hydrogen is 25 SCCM and the working pressure is 10 mtorr exactly similar to the hydrogenation of graphene surface [70].…”

Nonlinear optical response of doped monolayer and bilayer graphene: Length gauge tight-binding model

“…Regarding the latter, we consider the effect of doping on the quadratic response of non-centrosymmetric systems, such as graphene on SiC or hBN substrates [32][33][34] and hydrogenated graphene. [36][37][38]…”

Large magnetoresistance by Pauli blockade in hydrogenated graphene

“…Hydrogenation was performed in an ultra-high vacuum chamber with an atomic hydrogen beam produced by thermal cracking of molecular hydrogen in a tungsten capillary heated by electron arXiv:1802.08295v1 [cond-mat.mes-hall] 22 Feb 2018 beam bombardment [3]. Atomic hydrogen adsorbates create C-H bonds that disrupt the sp 2 lattice of graphene to create localized sp 3 distortions, with a profound effect on graphene's electronic properties [24,25]. The neutral point defect density per carbon atom induced by hydrogenation in our samples is on the order of parts per thousand, as inferred from Raman spectroscopy [3,4,26].…”