J 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

Štítky

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
Název: MSCAfellow2@MUNI
90110, velká výzkumná infrastruktura
Název: CzechNanoLab