High Electron Mobility in Epitaxial Graphene on 4H-SiC(0001) via post-growth annealing under hydrogen

Abstract

We investigate the magneto-transport properties of epitaxial graphene single-layer on 4H-SiC(0001), grown by atmospheric pressure graphitization in Ar, followed by H2 intercalation. We directly demonstrate the importance of saturating the Si dangling bonds at the graphene/SiC(0001) interface to achieve high carrier mobility. Upon successful Si dangling bonds elimination, carrier mobility increases from 3 000 cm2V−1s−1 to >11 000 cm2V−1s−1 at 0.3 K. Additionally, graphene electron concentration tends to decrease from a few 1012 cm−2 to less than 1012 cm−2. For a typical large (30 × 280 μm2) Hall bar, we report the observation of the integer quantum Hall states at 0.3 K with well developed transversal resistance plateaus at Landau level filling factors of ν = 2, 6, 10, 14… 42 and Shubnikov de Haas oscillation of the longitudinal resistivity observed from about 1 T. In such a device, the Hall state quantization at ν = 2, at 19 T and 0.3 K, can be very robust: the dissipation in electronic transport can stay very low, with the longitudinal resistivity lower than 5 mΩ, for measurement currents as high as 250 μA. This is very promising in the view of an application in metrology.

Electrolytic phototransistor based on graphene-MoS2 van der Waals p-n heterojunction with tunable photoresponse

“…The p-type graphene is obtained by hydrogenation of epitaxial graphene resulting from the high temperature baking of a SiC substrate 27,28 . The latter presents several advantages, in particular the lack of a transfer step between the growth and the device design.…”

Unveiling the carrier transport mechanism in epitaxial graphene for forming wafer-scale, single-domain graphene

“…clear contrast to our previous report where we have shown only crystallographic single crystallinity in graphene through LRGT due to the uncertainty of the quality of graphene near the terrace edges of SiC (26). Further elimination of the process residues during the LRGT leads to a notable maximum mobility of 7,496 cm 2 /V·s measured at room temperature for a single-crystalline, singledomain graphene transferred on a SiO 2 /Si substrate, which supersedes as the highest value ever reported from graphene formed on the Si face of an SiC wafer (15,16,(21)(22)(23)(27)(28)(29).…”

“…S5) is the highest value ever reported from the graphene grown on Si-face SiC wafer (Fig. S6) (15,16,(21)(22)(23)(27)(28)(29). It should be noted that, in our previous report (26), enhanced mobility due to flattening the epitaxial graphene is screened by the Ni residues on graphene after chemical etching of the Ni stressor.…”

Introduction

“…Quantum Hall transport measurements also observe the sequence of the LLs [203][204][205][206][207][208][209][210][211][212][213][214][215][216][217][218][219][220]. Furthermore, low-energy optical transitions with specified selection rules are verified for the intergroup LLs near = E 0 F in the infrared transmission, absorption and magneto-Raman spectra [75, 76, 136, 138, 139, 164, 166-168, 171-174, 177, 180, 181, 236-243].…”