2022
Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure
ROY, Rajarshi; David HOLEC; Markus KRATZER; Philipp MUENZER; Preeti KAUSHIK et al.Základní údaje
Originální název
Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure
Autoři
ROY, Rajarshi; David HOLEC; Markus KRATZER; Philipp MUENZER; Preeti KAUSHIK; Lukáš MICHAL; Gundam Sandeep KUMAR; Lenka ZAJÍČKOVÁ a Christian TEICHERT
Vydání
Nanotechnology, IOP Publishing Ltd. 2022, 0957-4484
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10305 Fluids and plasma physics
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 3.500
Kód RIV
RIV/00216224:14310/22:00128664
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000798066500001
EID Scopus
2-s2.0-85130862829
Klíčová slova anglicky
graphene; graphene quantum dots; scanning probe microscopy; charge transfer; ab initio
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 3. 4. 2023 12:18, Mgr. Marie Novosadová Šípková, DiS.
Anotace
V originále
In recent years, graphene-based van der Waals (vdW) heterostructures have come into prominence showcasing interesting charge transfer dynamics which is significant for optoelectronic applications. These novel structures are highly tunable depending on several factors such as the combination of the two-dimensional materials, the number of layers and band alignment exhibiting interfacial charge transfer dynamics. Here, we report on a novel graphene based 0D-2D vdW heterostructure between graphene and amine-functionalized graphene quantum dots (GQD) to investigate the interfacial charge transfer and doping possibilities. Using a combination of ab initio simulations and Kelvin probe force microscopy (KPFM) measurements, we confirm that the incorporation of functional GQDs leads to a charge transfer induced p-type doping in graphene. A shift of the Dirac point by 0.05 eV with respect to the Fermi level (E (F)) in the graphene from the heterostructure was deduced from the calculated density of states. KPFM measurements revealed an increment in the surface potential of the GQD in the 0D-2D heterostructure by 29 mV with respect to graphene. Furthermore, we conducted power dependent Raman spectroscopy for both graphene and the heterostructure samples. An optical doping-induced gating effect resulted in a stiffening of the G band for electrons and holes in both samples (graphene and the heterostructure), suggesting a breakdown of the adiabatic Born-Oppenheimer approximation. Moreover, charge imbalance and renormalization of the electron-hole dispersion under the additional influence of the doped functional GQDs is pointing to an asymmetry in conduction and carrier mobility.
Návaznosti
| EF18_070/0009846, projekt VaV |
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| 90110, velká výzkumná infrastruktura |
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