Investigation into the modelling of field-effect carrier mobility in disordered organic semiconductors

2006 ◽  
Vol 153 (2) ◽  
pp. 124 ◽  
Author(s):  
H. Kwok ◽  
Y.L. Wu ◽  
T.P. Sun
Keyword(s):  
Organic Semiconductors ◽  
Field Effect ◽  
Carrier Mobility

Bisperfluorophenyl-Substituted Thiophene Oligomers. Organic Semiconductors with Complementary-Type Carrier Mobility

2002 ◽  
Vol 736 ◽  
Author(s):  
Antonio Facchetti ◽  
Howard E. Katz ◽  
Tobin J. Marks
Keyword(s):  
Thin Films ◽  
Cyclic Voltammetry ◽  
Molecular Characterization ◽  
Organic Semiconductors ◽  
Field Effect ◽  
Carrier Mobility ◽  
Field Effect Transistor ◽  
Photoluminescence Spectroscopy ◽  
Design Synthesis ◽  
Effect Transistor

ABSTRACTThe design, synthesis, and properties of two mixed perfluorophenyl-thiophene oligomers 5,5″′-diperfluorophenyl-2,2′:5′,2″:5″,2″′:5″′,2″″:5″″,2″″′-quaterthiophene (2) and 5,5′-bis{1-[4-(thien-2-yl)-2,3,5,6-tetrafluorophenyl)] }-2,2′-dithiophene (3) are presented. Molecular characterization included the following techniques: multinuclear NMR, DSC and TGA, optical UV-Vis and photoluminescence spectroscopy, and cyclic voltammetry. Thin films can be easily grown by vacuum evaporation and have been characterized by optical UV-Vis and photoluminescence, XRD, and field-effect transistor measurements. Electron and hole mobilities of 0.06–0.08 cm2/(V s) and 0.001–0.003 cm2/(V s) were found for 2 and 3, respectively.

scholarly journals Polarization-induced transport in ferroelelctric organic field-effect transistors

2019 ◽  
Author(s):  
◽  
Amrit Prasad Laudari
Keyword(s):  
Organic Semiconductors ◽  
Small Molecule ◽  
Dielectric Layer ◽  
Field Effect ◽  
Polyvinylidene Fluoride ◽  
Carrier Mobility ◽  
Field Effect Transistors ◽  
Organic Field Effect Transistors ◽  
Sensing Applications ◽  
Organic Fets

In this research we study the role of ferroelectric dielectrics in organic field-effect transistors (FETs) to understand the mechanism of charge transport in organic semiconductors. The ferroelectric nature of the polymer, poly(vinylidene fluoride) (PVDF)), has been known for over 45 years. However, its role in interfacial transport in organic/polymeric FETs is not that well understood. PVDF and its copolymer, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), as a dielectric in organic FETs is a perfect test-bed for conducting transport studies where a systematic tuning of the dielectric constant with temperature may be achieved. By choosing small molecule organic semiconductors -- pentacene and 6,13 bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) -- along with a copolymer PVDF-TrFE as the dielectric layer, the FET characteristics are monitored as a function of temperature. Pentacene FETs show a weak temperature dependence of the charge carrier mobility in the ferroelectric phase of PVDF-TrFE, which is attributed to polarization fluctuation driven transport resulting from a coupling of the charge carriers to the surface phonons of the dielectric layer. A negative coefficient of carrier mobility is observed in TIPS-pentacene upwards of 200 K with the ferroelectric dielectric, while an activated transport is observed with non-ferroelectric dielectrics. We show that this behavior is correlated with the nature of the trap states in TIPS-pentacene. We also developed the method of dipole engineering of the PVDF-TrFE films to enhance the properties of organic FETs. PVDF-TrFE, despite its applications in a vast range of work (including as a gate dielectric in organic FET and sensing applications) poses concerns such as higher conductivity compared to other polymer non-ferroelectric dielectrics. We have come up with new methods of electrical poling the dielectric layer to enhance FET performance as well as reduce gate leakage issues. We demonstrate the effect of polarization rotation in PVDF-TrFE on the performance of small-molecule-based organic FETs. The subthreshold swing and other transistor parameters in organic FETs can be controlled in a reversible fashion by switching the polarization direction in the PVDF-TrFE layer. We further demonstrate a novel method of selective poling of the dielectric layer. By using solution processed TIPS-pentacene as the organic semiconductor, it is shown that textured poling of the PVDF-TrFE layer dramatically improves FET properties compared to unpoled or uniformly poled ferroelectric films. The texturing is achieved by first vertically poling the PVDF-TrFE film and then laterally poling the dielectric layer close to the gate electrode. TIPS-pentacene FETs show on/off ratios of 105 and hole mobilities of 1 cm2/Vs under ambient conditions with operating voltages well below-4 V. This research opens prospects of achieving low-operating FETs without any expensive patterning techniques.

scholarly journals Dithienylbenzothiadiazole-Based Donor-Acceptor Organic Semiconductors and Effect of End Capping Groups on Organic Field Effect Transistor Performance

2013 ◽  
Vol 66 (3) ◽  
pp. 370
Author(s):  
Prashant Sonar ◽  
Samarendra P. Singh ◽  
Ting Ting Lin ◽  
Ananth Dodabalapur
Keyword(s):  
Molecular Orbital ◽  
Organic Semiconductors ◽  
Field Effect ◽  
Carrier Mobility ◽  
Field Effect Transistor ◽  
Energy Levels ◽  
Lumo Energy ◽  
Donor Acceptor ◽  
Effect Transistor ◽  
End Capping

Donor-Acceptor-Donor (D-A-D) based conjugated molecules 4,7-bis(5-(4-butoxyphenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (BOP-TBT) and 4,7-bis(5-(4-trifluoromethyl)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole (TFP-TBT) using thiophene-benzothiadiazole-thiophene central core with trifluoromethyl phenyl and butoxyphenyl end capping groups were designed and synthesised via Suzuki coupling. Optical, electrochemical, thermal, and organic field effect transistor (OFET) device properties of BOP-TBT and TFP-TBT were investigated. Both small molecules possess two absorption bands. Optical band gaps were calculated from the absorption cut off to be in the range of 2.06–2.25 eV. Cyclic voltammetry indicated reversible oxidation and reduction processes and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels were calculated to be in the range of 5.15–5.40 eV and 3.25–3.62 eV, respectively. Upon testing both materials for OFET, trifluoromethylphenyl end capped material (TFP-TBT) shows n-channel behaviour whereas butoxyphenyl end capped material (BOP-TBT) shows p-channel behaviour. Density functional theory calculations correlated with shifting of HOMO-LUMO energy levels with respect to end capping groups. Vacuum processed OFET of these materials have shown highest hole carrier mobility of 0.02 cm2/Vs and electron carrier mobility of 0.004 cm2/Vs, respectively using Si/SiO2 substrate. By keeping the central D-A-D segment and just by tuning end capping groups gives both p- and n-channel organic semiconductors which can be prepared in a single step using straightforward synthesis.

Electron-Transporting Thiophene-Based Semiconductors Exhibiting Very High Field Effect Mobilities

2004 ◽  
Vol 814 ◽  
Author(s):  
Antonio Facchetti ◽  
Myung-Han Yoon ◽  
Tobin J. Marks
Keyword(s):  
Organic Semiconductors ◽  
Field Effect ◽  
Carrier Mobility ◽  
Field Effect Transistor ◽  
Thin Film Transistor ◽  
Structural Features ◽  
Improve Performance ◽  
Plastic Electronics ◽  
Effect Transistor ◽  
Very High

AbstractOrganic semiconductors exhibiting complementary n-type carrier mobility are the key components for the development of the field of “plastic electronics”. We present here a novel series of oligothiophenes designed to improve performance and stability under electron- transporting conditions. Furthermore, the key structural features of these compounds allows additional modifications of the n-type conducting core to achieve material solubility and processability. Thin film transistor (TFT) devices were fabricated employing both vacuum- and solution-deposited semiconducting layers. Field-effect transistor measurements indicate that all the members of this new series are n-type semiconductors with mobilities and Ion:Ioff ratios approaching 1 cm2/(Vs) and 107, respectively. This family represents a key milestone in the design, understanding, and development of the next generation of highly efficient n-type OTFT components.

High Carrier Mobility and Environmentally stable Microporous Zeolite Imidazolate Framework (ZIF-67): A Field-Effect Transistor (FET) Approach

2021 ◽  
pp. 138690
Author(s):  
Pasha W. Sayyad ◽  
Aafiya A. Farooqui ◽  
Nikesh N. Ingle ◽  
Theeazen Al-Gahouari ◽  
Gajanan A. Bodkhe ◽  
...  
Keyword(s):  
Field Effect ◽  
Carrier Mobility ◽  
Field Effect Transistor ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Effect Transistor ◽  
Microporous Zeolite

Conjugated Donor−Acceptor Copolymer Semiconductors. Synthesis, Optical Properties, Electrochemistry, and Field-Effect Carrier Mobility of Pyridopyrazine-Based Copolymers

2008 ◽  
Vol 41 (19) ◽  
pp. 7021-7028 ◽  
Author(s):  
Pei-Tzu Wu ◽  
Felix S. Kim ◽  
Richard D. Champion ◽  
Samson A. Jenekhe
Keyword(s):  
Optical Properties ◽  
Field Effect ◽  
Carrier Mobility ◽  
Donor Acceptor
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