Direct measurement of Dirac point and Fermi level at graphene/oxide interface by internal photoemission

2012 ◽  
Author(s):  
Kun Xu ◽  
Caifu Zeng ◽  
Qin Zhang ◽  
Peide Ye ◽  
Kang Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Fermi Level ◽  
Direct Measurement ◽  
Dirac Point ◽  
Oxide Interface ◽  
Internal Photoemission

scholarly journals Direct Measurement of Dirac Point Energy at the Graphene/Oxide Interface

Nano Letters ◽  
2012 ◽  
Vol 13 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Kun Xu ◽  
Caifu Zeng ◽  
Qin Zhang ◽  
Rusen Yan ◽  
Peide Ye ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Direct Measurement ◽  
Dirac Point ◽  
Oxide Interface ◽  
Point Energy

Enhancing the Power Conversion Efficiency of Inverted Organic Photovoltaics with Gold Functionalized Reduced Graphene Oxide

2015 ◽  
Vol 1737 ◽  
Author(s):  
Rebecca Isseroff ◽  
Zhenhua Yang ◽  
Jessica Kim ◽  
Andrew Chen ◽  
Miriam Rafailovich
Keyword(s):  
Graphene Oxide ◽  
Fermi Level ◽  
Reduced Graphene Oxide ◽  
Active Layer ◽  
Energy Gap ◽  
Power Conversion ◽  
Design Phase ◽  
Reduced Graphene ◽  
Exciton Recombination ◽  
First Time

ABSTRACTIn this study, an “inverted” design, phase-separated morphology and gold-functionalized reduced graphene oxide (Au-rGO) were used to address exciton recombination and poor Fermi level alignment. To increase efficiencies, a unique methodology was used to coat Au-rGO on top of the active layer. When 0.05 Au-rGO was blended with the active layer, there were metal-thiolate bonds with P3HT and π-π stacking with PCBM. However, KPFM, measured for the first time for this material, showed that the while 0.05mM Au-rGO reduced the energy gap between P3HT and PBCM, this was offset by recombination. KPFM showed that Au-rGO may be better suited between the active layer and electrode. When 0.5mM Au-rGO was coated on top of the active layer, efficiency increased (p<0.002) nearly 600%, suggesting that Au-rGO is a more effective acceptor than a constituent of the active layer.

Observation of Fermi level pinning at the GaAs-plasma-oxide interface

1987 ◽  
Vol 2 (10) ◽  
pp. 636-642 ◽  
Author(s):  
I Thurzo ◽  
E Pincik ◽  
M Morvic ◽  
T Gorog
Keyword(s):  
Fermi Level ◽  
Oxide Interface ◽  
Fermi Level Pinning

scholarly journals Effect of Ag2S Nanocrystals/Reduced Graphene Oxide Interface on Hydrogen Evolution Reaction

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 948
Author(s):  
Chen Zhao ◽  
Zhi Yu ◽  
Jun Xing ◽  
Yuting Zou ◽  
Huiwen Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Fossil Fuels ◽  
Composite Catalyst ◽  
Oxide Interface ◽  
Electrochemical Catalyst ◽  
Reduced Graphene

The development of efficient electrocatalyst to produce molecular hydrogen from water is receiving considerable attention, in an effort to decrease our reliance on fossil fuels. The prevention of the aggregation of active sites during material synthesis, in order to increase charge transport properties of electrocatalysts, is needed. We have designed, synthesized, and studied a Ag2S/reduced graphene oxide (rGO) electrochemical catalyst (for hydrogen evolution) from water. The Ag2S nanocrystals were synthesized by the solvothermal method in which the rGO was added. The addition of the rGO resulted in the formation of smaller Ag2S nanocrystals, which consequently increased the electrical conductivity of the composite catalyst. The composite catalyst showed a higher electrochemical catalytic activity than the one with an absence of rGO. At a current density of 10 mA/cm2, a low overpotential of 120 mV was obtained. A Tafel slope of 49.1 mV/dec suggests a Volmer–Herovsky mechanism for the composite catalyst. These results may provide a novel strategy for developing hydrogen evolution reaction (HER) electrocatalysts, via the combining of a nano-semiconductor catalyst with a 2D material.

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.

scholarly journals Intercalation of Mn in graphene/Cu(111) interface: insights to the electronic and magnetic properties from theory

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qilin Guo ◽  
Yuriy Dedkov ◽  
Elena Voloshina
Keyword(s):  
Fermi Level ◽  
Density Functional ◽  
Dirac Point ◽  
State Of The Art ◽  
Structural Models ◽  
Electronic States ◽  
Density Functional Theory Calculations ◽  
Linear Dispersion ◽  
Functional Theory ◽  
Favorable Configuration

AbstractThe effect of Mn intercalation on the atomic, electronic and magnetic structure of the graphene/Cu(111) interface is studied using state-of-the-art density functional theory calculations. Different structural models of the graphene–Mn–Cu(111) interface are investigated. While a Mn monolayer placed between graphene and Cu(111) (an unfavorable configuration) yields massive rearrangement of the graphene-derived $$\pi $$ π bands in the vicinity of the Fermi level, the possible formation of a $$\hbox {Cu}_2$$ Cu 2 Mn alloy at the interface (a favorable configuration) preserves the linear dispersion for these bands. The deep analysis of the electronic states around the Dirac point for the graphene/$$\hbox {Cu}_2$$ Cu 2 Mn/Cu(111) system allows to discriminate between contributions from three carbon sublattices of a graphene layer in this system and to explain the bands’ as well as spins’ topology of the electronic states around the Fermi level.

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