Reply to: Dirac-point photocurrents due to photothermoelectric effect in non-uniform graphene devices

2020 ◽  
Vol 15 (4) ◽  
pp. 244-246
Author(s):  
Qiong Ma ◽  
Justin C. W. Song ◽  
Nathaniel M. Gabor ◽  
Pablo Jarillo-Herrero
Keyword(s):  
Dirac Point ◽  
Graphene Devices

scholarly journals Positioning of the Fermi Level in Graphene Devices with Asymmetric Metal Electrodes

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Bum-Kyu Kim ◽  
Eun-Kyoung Jeon ◽  
Ju-Jin Kim ◽  
Jeong-O Lee
Keyword(s):  
Fermi Level ◽  
Dirac Point ◽  
Metal Electrode ◽  
Peak Position ◽  
Metal Contacts ◽  
Metal Electrodes ◽  
Hole Band ◽  
Graphene Devices ◽  
Hybrid Devices ◽  
Bias Range

To elucidate the effect of the work function on the position of the Dirac point, we fabricated graphene devices with asymmetric metal contacts. By measuring the peak position of the resistance for each pair of metal electrodes, we obtained the voltage of the Dirac pointVgDirac(V) from the gate response. We found that the position ofVgDirac(V) in the hybrid devices was significantly influenced by the type of metal electrode. The measured shifts inVgDirac(V) were closely related to the modified work functions of the metal-graphene complexes. Within a certain bias range, the Fermi level of one of the contacts aligned with the electron band and that of the other contact aligned with the hole band.

Selective n-type doping in graphene via the aluminium nanoparticle decoration approach

2014 ◽  
Vol 2 (27) ◽  
pp. 5417-5421 ◽  
Author(s):  
Xiaoling Shi ◽  
Guofa Dong ◽  
Ming Fang ◽  
Fengyun Wang ◽  
Hao Lin ◽  
...  
Keyword(s):  
Dirac Point ◽  
Effective Technique ◽  
Current Ratio ◽  
Al Nanoparticles ◽  
Left Shift ◽  
Graphene Devices

A simple and effective technique is presented to left shift the Dirac point of graphene transistors to induce n-type doping via the thermal decoration of Al nanoparticles. The versatility of this approach is illustrated by the fabrication of air-stable n-type doping in graphene devices with the improved on/off current ratio.

scholarly journals Ultra-low contact resistance in graphene devices at the Dirac point

2D Materials ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 025014 ◽  
Author(s):  
Luca Anzi ◽  
Aida Mansouri ◽  
Paolo Pedrinazzi ◽  
Erica Guerriero ◽  
Marco Fiocco ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Dirac Point ◽  
Graphene Devices

Chemistry at the Dirac Point of Graphene: Diels-Alder Approach to Reversible Band Gap Engineering and High Mobility Graphene Devices

2014 ◽  
Vol 1658 ◽  
Author(s):  
Santanu Sarkar
Keyword(s):  
Band Gap ◽  
Dirac Point ◽  
High Mobility ◽  
Single Layer ◽  
Diels Alder ◽  
Single Layer Graphene ◽  
Dual Nature ◽  
Band Gap Engineering ◽  
Graphene Devices ◽  
Graphene Fet

ABSTRACTThe Diels-Alder (DA) pericyclic chemistry is one of the most powerful reactions in synthetic chemistry. We have recently shown that the unique zero-band-gap electronic structure of graphene at the Dirac point facilitates the band-gap-dependent DA reaction of graphene, although graphene is the thermochemical reference for carbon. We have shown that in the DA reactions, graphene can function either as a diene or a dienophile (dual nature). Such DA functionalization of graphene when applied to graphene-FET devices allows balanced functionalization (creation of a pair of new sp3 centers or divacancies) at both A and B graphene sublattices, allowing the fabrication of high mobility DA-functionalized single-layer graphene devices (DA-SLG) with acceptable on/off ratio. The chemistry is thermally reversible via retro-DA chemistry, thus allowing reversible engineering of graphene devices.

scholarly journals Dirac-point photocurrents due to the photothermoelectric effect in non-uniform graphene devices

2020 ◽  
Vol 15 (4) ◽  
pp. 241-243 ◽  
Author(s):  
Michael S. Fuhrer ◽  
Nikhil V. Medhekar
Keyword(s):  
Dirac Point ◽  
Graphene Devices

scholarly journals Global strain-induced scalar potential in graphene devices

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Lujun Wang ◽  
Andreas Baumgartner ◽  
Péter Makk ◽  
Simon Zihlmann ◽  
Blesson Sam Varghese ◽  
...  
Keyword(s):  
Dirac Point ◽  
Direct Evidence ◽  
Electronic Device ◽  
Scalar Potential ◽  
Energy Shift ◽  
Global Strain ◽  
Optical And Electronic Properties ◽  
Similar Materials ◽  
Graphene Devices ◽  
External Strain

AbstractBy mechanically distorting a crystal lattice it is possible to engineer the electronic and optical properties of a material. In graphene, one of the major effects of such a distortion is an energy shift of the Dirac point, often described as a scalar potential. We demonstrate how such a scalar potential can be generated systematically over an entire electronic device and how the resulting changes in the graphene work function can be detected in transport experiments. Combined with Raman spectroscopy, we obtain a characteristic scalar potential consistent with recent theoretical estimates. This direct evidence for a scalar potential on a macroscopic scale due to deterministically generated strain in graphene paves the way for engineering the optical and electronic properties of graphene and similar materials by using external strain.

Graphene–polyimide-integrated metasurface for ultrasensitive modulation of higher-order terahertz fano resonances at the Dirac point

2021 ◽  
pp. 150182
Author(s):  
Maosheng Yang ◽  
Tengteng Li ◽  
Ju Gao ◽  
Xin Yan ◽  
Lanju Liang ◽  
...  
Keyword(s):  
Dirac Point ◽  
Higher Order ◽  
Fano Resonances

scholarly journals Discovery of a weak topological insulating state and van Hove singularity in triclinic RhBi2

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kyungchan Lee ◽  
Gunnar F. Lange ◽  
Lin-Lin Wang ◽  
Brinda Kuthanazhi ◽  
Thaís V. Trevisan ◽  
...  
Keyword(s):  
Time Reversal ◽  
Topological Insulators ◽  
Dirac Point ◽  
Saddle Points ◽  
Surface States ◽  
Van Hove Singularity ◽  
Space Group ◽  
Topological Materials ◽  
Topological Surface ◽  
Optimal Space

AbstractTime reversal symmetric (TRS) invariant topological insulators (TIs) fullfil a paradigmatic role in the field of topological materials, standing at the origin of its development. Apart from TRS protected strong TIs, it was realized early on that more confounding weak topological insulators (WTI) exist. WTIs depend on translational symmetry and exhibit topological surface states only in certain directions making it significantly more difficult to match the experimental success of strong TIs. We here report on the discovery of a WTI state in RhBi2 that belongs to the optimal space group P$$\bar{1}$$ 1 ¯ , which is the only space group where symmetry indicated eigenvalues enumerate all possible invariants due to absence of additional constraining crystalline symmetries. Our ARPES, DFT calculations, and effective model reveal topological surface states with saddle points that are located in the vicinity of a Dirac point resulting in a van Hove singularity (VHS) along the (100) direction close to the Fermi energy (EF). Due to the combination of exotic features, this material offers great potential as a material platform for novel quantum effects.

scholarly journals Emergent flat band electronic structure in a VSe2/Bi2Se3 heterostructure

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Turgut Yilmaz ◽  
Xiao Tong ◽  
Zhongwei Dai ◽  
Jerzy T. Sadowski ◽  
Eike F. Schwier ◽  
...  
Keyword(s):  
Dirac Point ◽  
Electronic States ◽  
Quantum States ◽  
Photoemission Spectroscopy ◽  
Flat Band ◽  
Strongly Correlated ◽  
Dirac Cone ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Topological Materials ◽  
Photoemission Study

AbstractFlat band electronic states are proposed to be a fundamental tool to achieve various quantum states of matter at higher temperatures due to the enhanced electronic correlations. However, materials with such peculiar electronic states are rare and often rely on subtle properties of the band structures. Here, by using angle-resolved photoemission spectroscopy, we show the emergent flat band in a VSe2 / Bi2Se3 heterostructure. Our photoemission study demonstrates that the flat band covers the entire Brillouin zone and exhibits 2D nature with a complex circular dichroism. In addition, the Dirac cone of Bi2Se3 is not reshaped by the flat band even though they overlap in proximity of the Dirac point. These features make this flat band distinguishable from the ones previously found. Thereby, the observation of a flat band in the VSe2 / Bi2Se3 heterostructure opens a promising pathway to realize strongly correlated quantum effects in topological materials.

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