scholarly journals Tuning the charge carriers in epitaxial graphene on SiC(0001) from electron to hole via molecular doping with C60F48

2013 ◽  
Vol 102 (24) ◽  
pp. 241601 ◽  
Author(s):  
A. Tadich ◽  
M. T. Edmonds ◽  
L. Ley ◽  
F. Fromm ◽  
Y. Smets ◽  
...  
Keyword(s):  
Epitaxial Graphene ◽  
Charge Carriers ◽  
Molecular Doping

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

scholarly journals Molecular Doping in Multi-Molecule Polymer-Dopant Complexes Shows Reduced Coulomb Binding

2020 ◽  
Author(s):  
Chuanding Dong ◽  
Stefan Schumacher
Keyword(s):  
Charge Transfer ◽  
Organic Semiconductors ◽  
Positive Charge ◽  
Charge Carriers ◽  
Mechanistic Study ◽  
Charge Transfer Complexes ◽  
Mobile Charge ◽  
Molecular Doping ◽  
Gap States ◽  
P Type

<p>The mechanistic study of molecular doping of organic semiconductors (OSC) requires</p><p>an improved understanding of the role and formation of integer charge transfer complexes</p><p>(ICTC) on a microscopic level. In the present work we go one crucial step beyond</p><p>the simplest scenario of an isolated bi-molecular ICTC and study ICTCs formed of</p><p>up to two (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b,3,4-b”]dithiophene)-alt-4,7-(2,1,3-</p><p>benzothiadiazole)](PCPDT-BT) oligomers and up to two CN6-CP molecules. We find that depending</p><p>on geometric arrangement, complexes containing two conjugated oligomers and two</p><p>dopant molecules can show p-type doping with double integer charge transfer, resulting in either</p><p>two singly doped oligomers or one doubly doped oligomer. Interestingly, compared to an individual</p><p>oligomer-dopant complex, the resulting in-gap states on the doped oligomers are significantly</p><p>lowered in energy. Indicating that, already in the relatively small systems studied here, Coulomb</p><p>binding of the doping-induced positive charge to the counter-ion is reduced which is an elemental</p><p>step towards generating mobile charge carriers through molecular doping.</p>

Top-gate dielectric induced doping and scattering of charge carriers in epitaxial graphene

2011 ◽  
Vol 99 (1) ◽  
pp. 013103 ◽  
Author(s):  
Conor P. Puls ◽  
Neal E. Staley ◽  
Jeong-Sun Moon ◽  
Joshua A. Robinson ◽  
Paul M. Campbell ◽  
...  
Keyword(s):  
Gate Dielectric ◽  
Epitaxial Graphene ◽  
Charge Carriers

scholarly journals Carbon-Free Solution-Based Doping for Silicon

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2006
Author(s):  
Sebastiano Caccamo ◽  
Rosaria Anna Puglisi
Keyword(s):  
Phosphoric Acid ◽  
Surface Density ◽  
Organic Molecules ◽  
Charge Carriers ◽  
Free Solution ◽  
Liquid Solutions ◽  
Molecular Doping ◽  
Material Forming ◽  
High Repeatability

Molecular doping is a method to dope semiconductors based on the use of liquid solutions as precursors of the dopant. The molecules are deposited on the material, forming a self-ordered monolayer that conforms to the surfaces, whether they are planar or structured. So far, molecular doping has been used with precursors of organic molecules, which also release the carbon in the semiconductor. The carbon atoms, acting as traps for charge carriers, deteriorate the doping efficiency. For rapid and extensive industrial exploitation, the need for a method that removes carbon has therefore been raised. In this paper, we use phosphoric acid as a precursor of the dopant. It does not contain carbon and has a smaller steric footprint than the molecules used in the literature, thus allowing a much higher predetermined surface density. We demonstrate doses of electrical carriers as high as 3 × 1015 #/cm2, with peaks of 1 × 1020 #/cm3, and high repeatability of the process, indicating an outstanding yield compared to traditional MD methods.

scholarly journals Controlling the Film Microstructure in Organic Thermoelectrics

2021 ◽  
Vol 03 (01) ◽  
pp. 001-016
Author(s):  
Miao Xiong ◽  
Jie-Yu Wang ◽  
Jian Pei
Keyword(s):  
Conjugated Polymers ◽  
High Performance ◽  
Electronic Devices ◽  
Charge Carrier Concentration ◽  
Charge Carriers ◽  
Organic Electronic Devices ◽  
Coulombic Interactions ◽  
Recent Developments ◽  
Heterogeneous Doping ◽  
Molecular Doping

Doping is a vital method to increase the charge carrier concentration of conjugated polymers, thus improving the performance of organic electronic devices. However, the introduction of dopants may cause phase separation. The miscibility of dopants and polymers as well as the doping-induced microstructure change are always the barriers in the way to further enhance the thermoelectrical performance. Here, recent research studies about the influence of molecular doping on the microstructures of conjugated polymers are summarized, with an emphasis on the n-type doping. Highlighted topics include how to control the distribution and density of dopants within the conjugated polymers by modulating the polymer structure, dopant structure, and solution-processing method. The strong Coulombic interactions between dopants and polymers as well as the heterogeneous doping process of polymers can hinder the polymer film to achieve better miscibility of dopants/polymer and further loading of the charge carriers. Recent developments and breakthroughs provide guidance to control the film microstructures in the doping process and achieve high-performance thermoelectrical materials.

scholarly journals Understanding the evolution of the Raman spectra of molecularly p-doped poly(3-hexylthiophene-2,5-diyl): signatures of polarons and bipolarons

2022 ◽  
Author(s):  
Ahmed E. Mansour ◽  
Ana Valencia ◽  
Dominique Lungwitz ◽  
Berthold Wegner ◽  
Naoki Tanaka ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Organic Semiconductors ◽  
Charge Carriers ◽  
Polymer Semiconductors ◽  
Molecular Doping

Molecular doping is a key process to increase the density of charge carriers in organic semiconductors. Doping-induced charges in polymer semiconductors result in the formation of polarons and/or bipolarons due...

scholarly journals Charge neutrality and band-gap tuning of epitaxial graphene on SiC by molecular doping

2010 ◽  
Vol 81 (23) ◽  
Author(s):  
C. Coletti ◽  
C. Riedl ◽  
D. S. Lee ◽  
B. Krauss ◽  
L. Patthey ◽  
...  
Keyword(s):  
Band Gap ◽  
Epitaxial Graphene ◽  
Charge Neutrality ◽  
Molecular Doping ◽  
Band Gap Tuning

Detector strategies for environmental scanning electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1296-1297
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
High Vacuum ◽  
Environmental Scanning Electron Microscopy ◽  
Charge Carriers ◽  
Environmental Scanning ◽  
Surface Information ◽  
X Ray ◽  
Detector Electrode ◽  
Electrons And Ions ◽  
Low Energy Electrons ◽  
Environmental Sem

Environmental SEM operate at specimen chamber pressures of ∼20 torr (2.7 kPa) allowing stabilization of liquid water at room temperature, working on rugged insulators, and generation of an environmental secondary electron (ESE) signal. All signals available in conventional high vacuum instruments are also utilized in the environmental SEM, including BSE, SE, absorbed current, CL, and X-ray. In addition, the ESEM allows utilization of the flux of charge carriers as information, providing exciting new signal modes not available to BSE imaging or to conventional high vacuum SEM.In the ESEM, at low vacuum, SE electrons are collected with a “gaseous detector”. This detector collects low energy electrons (and ions) with biased wires or plates similar to those used in early high vacuum SEM for SE detection. The detector electrode can be integrated into the first PLA or positioned at any other place resulting in a versatile system that provides a variety of surface information.

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