ROY, Rajarshi, David HOLEC, Markus KRATZER, Philipp MUENZER, Preeti KAUSHIK, Lukáš MICHAL, Gundam Sandeep KUMAR, Lenka ZAJÍČKOVÁ and Christian TEICHERT. Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure. Nanotechnology. IOP Publishing Ltd., 2022, vol. 33, No 32, p. 1-9. ISSN 0957-4484. Available from: https://dx.doi.org/10.1088/1361-6528/ac6c38. |
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@article{2256280, author = {Roy, Rajarshi and Holec, David and Kratzer, Markus and Muenzer, Philipp and Kaushik, Preeti and Michal, Lukáš and Kumar, Gundam Sandeep and Zajíčková, Lenka and Teichert, Christian}, article_number = {32}, doi = {http://dx.doi.org/10.1088/1361-6528/ac6c38}, keywords = {graphene; graphene quantum dots; scanning probe microscopy; charge transfer; ab initio}, language = {eng}, issn = {0957-4484}, journal = {Nanotechnology}, title = {Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure}, url = {https://doi.org/10.1088/1361-6528/ac6c38}, volume = {33}, year = {2022} }
TY - JOUR ID - 2256280 AU - Roy, Rajarshi - Holec, David - Kratzer, Markus - Muenzer, Philipp - Kaushik, Preeti - Michal, Lukáš - Kumar, Gundam Sandeep - Zajíčková, Lenka - Teichert, Christian PY - 2022 TI - Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure JF - Nanotechnology VL - 33 IS - 32 SP - 1-9 EP - 1-9 PB - IOP Publishing Ltd. SN - 09574484 KW - graphene KW - graphene quantum dots KW - scanning probe microscopy KW - charge transfer KW - ab initio UR - https://doi.org/10.1088/1361-6528/ac6c38 N2 - 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. ER -
ROY, Rajarshi, David HOLEC, Markus KRATZER, Philipp MUENZER, Preeti KAUSHIK, Lukáš MICHAL, Gundam Sandeep KUMAR, Lenka ZAJÍČKOVÁ and Christian TEICHERT. Probing the charge transfer and electron-hole asymmetry in graphene-graphene quantum dot heterostructure. \textit{Nanotechnology}. IOP Publishing Ltd., 2022, vol.~33, No~32, p.~1-9. ISSN~0957-4484. Available from: https://dx.doi.org/10.1088/1361-6528/ac6c38.
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