scholarly journals Demonstration of the key substrate-dependent charge transfer mechanisms between monolayer MoS2 and molecular dopants

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Soohyung Park ◽  
Thorsten Schultz ◽  
Xiaomin Xu ◽  
Berthold Wegner ◽  
Areej Aljarb ◽  
...  

Abstract Tuning the Fermi level (EF) in two-dimensional transition metal dichalcogenide (TMDC) semiconductors is crucial for optimizing their application in (opto-)electronic devices. Doping by molecular electron acceptors and donors has been suggested as a promising method to achieve EF-adjustment. Here, we demonstrate that the charge transfer (CT) mechanism between TMDC and molecular dopant depends critically on the electrical nature of the substrate as well as its electronic coupling with the TMDC. Using angle-resolved ultraviolet and X-ray photoelectron spectroscopy, we reveal three fundamentally different, substrate-dependent CT mechanisms between the molecular electron acceptor 1,3,4,5,7,8-hexafluoro-tetracyano-naphthoquinodimethane (F6TCNNQ) and a MoS2 monolayer. Our results demonstrate that any substrate that acts as charge reservoir for dopant molecules can prohibit factual doping of a TMDC monolayer. On the other hand, the three different CT mechanisms can be exploited for the design of advanced heterostructures, exhibiting tailored electronic properties in (opto-)electronic devices based on two-dimensional semiconductors.

Author(s):  
Diogo José Horst ◽  
Charles Adriano Duvoisin ◽  
Rogério De Almeida Vieira ◽  
Jesús Alejandro Arizpe ◽  
Esther Alejandra Huitrón Segovia ◽  
...  

The main objective of this work was to study the synthesis and characteristics of two-dimensional heterostructures (2D/2D) using pure molybdenum disulfide (MoS[Formula: see text] and doped with phosphorus at 5% and 15% combined with graphene oxide (GO) and graphene monolayer. These were deposited on silicon and copper substrates using two different deposition methods: Microdrop casting and chemical vapor deposition. Chemical and structural information of the samples were characterized by Raman spectroscopy, Energy Dispersion X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM) and Kelvin Probe Force Microscopy (KPFM). The results prove the synergy between the materials resulting in electronic coupling, making this system potential for applications in electronic devices such as sensors, resistors and capacitors.


2006 ◽  
Vol 132 ◽  
pp. 87-90
Author(s):  
M. El Kazzi ◽  
G. Delhaye ◽  
S. Gaillard ◽  
E. Bergignat ◽  
G. Hollinger

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Qiyang Lu ◽  
Henrique Martins ◽  
Juhan Matthias Kahk ◽  
Gaurab Rimal ◽  
Seongshik Oh ◽  
...  

AbstractWhen a three-dimensional material is constructed by stacking different two-dimensional layers into an ordered structure, new and unique physical properties can emerge. An example is the delafossite PdCoO2, which consists of alternating layers of metallic Pd and Mott-insulating CoO2 sheets. To understand the nature of the electronic coupling between the layers that gives rise to the unique properties of PdCoO2, we revealed its layer-resolved electronic structure combining standing-wave X-ray photoemission spectroscopy and ab initio many-body calculations. Experimentally, we have decomposed the measured VB spectrum into contributions from Pd and CoO2 layers. Computationally, we find that many-body interactions in Pd and CoO2 layers are highly different. Holes in the CoO2 layer interact strongly with charge-transfer excitons in the same layer, whereas holes in the Pd layer couple to plasmons in the Pd layer. Interestingly, we find that holes in states hybridized across both layers couple to both types of excitations (charge-transfer excitons or plasmons), with the intensity of photoemission satellites being proportional to the projection of the state onto a given layer. This establishes satellites as a sensitive probe for inter-layer hybridization. These findings pave the way towards a better understanding of complex many-electron interactions in layered quantum materials.


Nanoscale ◽  
2021 ◽  
Author(s):  
Daniel Vaquero ◽  
Vito Clericò ◽  
Juan Salvador-Sanchez ◽  
Elena Díaz ◽  
Francisco Dominguez-Adame ◽  
...  

Two-dimensional transition metal dichalcogenide (TMD) phototransistors have been object of intensive research during the last years due to their potential for photodetection. Photoresponse in these devices is typically caused by...


1998 ◽  
Vol 05 (01) ◽  
pp. 387-392 ◽  
Author(s):  
D. Abriou ◽  
D. Gagnot ◽  
J. Jupille ◽  
F. Creuzet

The growth mode of silver films deposited at room temperature on TiO 2(110) surfaces has been examined by means of atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) in ultrahigh vacuum (UHV) conditions, On clean vacancy-free TiO 2(110) surfaces, 0.1-nm-thick (on average) Ag deposits form a two-dimensional (2D) layer. When the thickness of the silver overlayer is increased, 3D clusters are shown to appear while the 2D film is preserved, furthermore, the influence of surface oxygen vacancies on the growth of Ag/TiO 2(110) is evidenced by well-characterized differences in the morphology of 9-nm-thick silver deposits.


2013 ◽  
Vol 802 ◽  
pp. 279-283
Author(s):  
Annop Chanhom ◽  
Pakorn Prajuabwan ◽  
Sunit Rojanasuwan ◽  
Anuchit Jaruvanawat ◽  
Adirek Rangkasikorn ◽  
...  

We investigate the increase of C-H vibration in benzene rings of pentacene molecule upon doping with indium by the X-ray photoelectron spectroscopy (XPS) characterization technique. The risen of C-H vibration spectral component is employed to demonstrate the charge transfer between In dopant atoms and C atoms in benzene rings of pentacene molecule. This experiment can be used to explain the same mechanism of charge transfer between In dopant atoms and C atoms in In-doped nickel-phthalocyanine(NiPc).


2019 ◽  
Vol 205 ◽  
pp. 05021
Author(s):  
Johannes Mahl ◽  
Stefan Neppl ◽  
Friedrich Roth ◽  
Andrey Shavorskiy ◽  
Nils Huse ◽  
...  

Photo-induced charge carrier dynamics and transient interfacial fields at the interface between N3 polypyridine complexes and films of nanocrystalline ZnO are probed by picosecond time-resolved X-ray photoelectron spectroscopy.


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