Donor-acceptor copolymers and sol-gel processable zinc oxide for thin film transistors and hybrid photodetectors

2019 ◽  
Author(s):  
◽  
Alec Pickett
Keyword(s):  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
Sol Gel ◽  
Phenyl Group ◽  
Grazing Incidence ◽  
Second Phase ◽  
Commercial Development ◽  
University Of Missouri ◽  
Pi Conjugated ◽  
P Type

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Organic semiconductors have been gaining attention both in research and commercial development for electronic devices due to their low manufacturing and processing costs. Copolymers based on diketopyrrolopyrrole (DPP) cores have attracted a lot of attention due to their high p-type as well as n-type carrier mobilities in organic field-effect transistors (FETs) and high power conversion efficiencies in solar cell structures. Hybrid organic-inorganic photodiode interfaces have also gained significant interest due to the realization of intrinsic p-n junctions as well as their unique physical properties such as mechanical flexibility and high photosensitivity. ZnO is an intrinsic n-type semiconductor which is non-toxic and sol-gel processable, creating avenues for film patterning and fully solution processed devices. In this work, we report the structural and charge transport properties of n-dialkyl side-chain substituted thiophene DPP end-capped with a phenyl group (Ph-TDPP-Ph) monomer in FETs which were fabricated by vacuum deposition and solvent casting. From grazing incidence X-ray diffraction (GIXRD), Ph-TDPP-Ph reveals polymorphic structure with [pi]-conjugated stacking direction oriented in-plane. The unit cell comprises either one monomer for one phase (TR1), or two monomers for the second phase (TR2). The TR2 phase thus signals a shift from a coplanar to herringbone orientation of the molecules. The device performance is sensitive to the ratio of the two triclinic phases found in the film. Some of the best FET performances with p-type carrier mobilities of 0.1 cm2/Vs and on/off ratio of 10[superscript 6] are for films that comprise mainly the TR1 phase.

scholarly journals 2,2'-(Arylenedivinylene)bis-8-hydroxyquinolines exhibiting aromatic π-π stacking interactions as solution-processable p-type organic semiconductors for high-performance organic field effect transistors

2021 ◽  
Author(s):  
Suman Yadav ◽  
Shivani Sharma ◽  
Satinder K Sharma ◽  
Chullikkattil P. Pradeep
Keyword(s):  
Organic Semiconductors ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
Field Effect Transistors ◽  
Organic Field Effect Transistors ◽  
Organic Thin Film ◽  
Effect Transistor ◽  
Solution Processable ◽  
P Type

Solution-processable organic semiconductors capable of functioning at low operating voltages (~5 V) are in demand for organic field-effect transistor (OFET) applications. Exploration of new classes of compounds as organic thin-film...

scholarly journals Material Design Inputs from Charge Density Analysis in Organic Semiconductors

2014 ◽  
Vol 70 (a1) ◽  
pp. C1552-C1552
Author(s):  
Venkatesha Hathwar ◽  
Mads Jørgensen ◽  
Mattia Sist ◽  
Jacob Overgaard ◽  
Bo Iversen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Electron Density ◽  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
High Mobility ◽  
Material Design ◽  
Detailed Comparison ◽  
Light Emitting ◽  
Density Analysis ◽  
P Type

In recent years, semiconducting organic materials have attracted a considerable amount of interest to develop all-organic or hybrid organic-inorganic electronic devices such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), or photovoltaic cells. Rubrene (5,6,11,12-tetraphenyltetracene, RUB) is one of the most explored compound in this area as it has nearly 100% fluorescence quantum efficiency in solution. Additionally, the OFET fabricated by vacuum-deposited using orthorhombic rubrene single crystals show p-type characteristics with high mobility up to 20cm2/Vs (Podzorov et al., 2004). The large charge-carrier mobilities measured have been attributed to the packing motif (Fig a) which provides enough spatial overlap of the π-conjugated tetracene backbone. In the same time, RUB undergoes an oxidation in the presence of light to form rubrene endoperoxide (RUB-OX) (Fumagalli et al., 2011). RUB-OX molecules show electronic and structural properties strikingly different from those of RUB, mainly due to the disruption in the conjugate stacking of tetracene moieties. The significant semiconducting property of RUB is not clear yet. In this context, high resolution single crystal X-ray data of RUB (Fig b) and RUB-OX have been collected at 100K. Owing to the presence of weak aromatic stacking and quadrupolar interactions, the neutron single crystal data is also collected at 100K. The C-H bond distances and scaled anisotropic displacement parameters (ADP) of hydrogens from the neutron experiment are used in the multipolar refinements of electron density. The chemical bonding features (Fig c), the topology of electron density and strength of weak interaction are calculated by the Atoms in Molecules (AIM) theory (Bader, 1990). It is further supported by the source function description and mapping of non-covalent interactions based on the electron density. The detailed comparison of two organic semiconductors, RUB and RUB-OX will be discussed.

Surface Plasmon-mediated Luminescence in Organic Field-effect Transistors

2007 ◽  
Vol 1029 ◽  
Author(s):  
Akira Watanabe ◽  
Hirokazu Tada
Keyword(s):  
Organic Semiconductors ◽  
Light Emission ◽  
Field Effect Transistors ◽  
Light Emitting ◽  
Gate Electrodes ◽  
Potential Applications ◽  
Drain Electrode ◽  
P Type ◽  
Metal Wires ◽  
Minority Carriers

AbstractConsiderable attention has recently been paid to light-emitting organic filed-effect transistors (LEOFETs) because of their potential applications to novel opto-electronic devices. In most LEOFETs, light emission occurs through the recombination of carriers injected from electrodes. Various efforts have been, thus, made to improve injection and transport properties of minority carriers in organic materials. On the other hand, light emission was frequently observed when we applied reverse bias voltages, that is, positive bias voltages, to the drain electrode for p-type FETs with grounded source and negatively biased gate electrodes. In this circuit, minority carriers were not injected into organic semiconductors. Nevertheless, the luminous intensity increased with drain voltage.In the present work, we have prepared such novel type LEOFETs with various device structures. We have inserted thin metal wires between the source and drain electrodes in the channel region of pentacene FETs. It was found that the light emission was observed around the metal wires inserted and the luminous efficiency was improved with the number of wires. The luminescence spectrum was identical to that of pentacene films. The light emission was thought to be generated by via energy transfer to the pentacene films from plasmon excited on metal surfaces by current injection.

Fullerene Based n-type Organic Thin-Film Transistors

2005 ◽  
Vol 871 ◽  
Author(s):  
Joshua Haddock ◽  
Benoit Domercq ◽  
Bernard Kippelen
Keyword(s):  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
High Vacuum ◽  
Channel Length ◽  
Organic Films ◽  
Limiting Factor ◽  
Organic Field Effect Transistors ◽  
Organic Thin Film ◽  
P Type ◽  
Made In

AbstractSignificant progress has been made in the area of p-type organic field effect transistors while progress in developing n-type materials and devices has been comparatively lacking, a limiting factor in the pursuit to develop complementary organic electronic circuits. Given the need for n-type organic semiconductors we have carried out studies using two different fullerene molecules, C60 and C70. Here, we report mobilities for C60 ranging from 0.02 cm2/Vs up to 0.65 cm2/Vs (depending on channel length), and mobilities from 0.003 cm2/Vs up to 0.066 cm2/Vs for C70. All devices were fabricated with organic films deposited under high vacuum but tested at ambient pressures under nitrogen.

scholarly journals Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

2016 ◽  
Vol 12 ◽  
pp. 805-812 ◽  
Author(s):  
Minh Anh Truong ◽  
Koji Nakano
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Organic Semiconductors ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Photoluminescence Spectroscopy ◽  
Organic Field Effect Transistors ◽  
Semiconducting Properties ◽  
P Type ◽  
Conjugated Compounds

Ladder-type π-conjugated compounds containing a benzo[2,1-b:3,4-b']difuran skeleton, such as dibenzo[d,d']benzo[2,1-b:3,4-b']difuran (syn-DBBDF) and dinaphtho[2,3-d:2',3'-d']benzo[2,1-b:3,4-b']difuran (syn-DNBDF) were synthesized. Their photophysical and electrochemical properties were revealed by UV–vis absorption and photoluminescence spectroscopy and cyclic voltammetry. Organic field-effect transistors (OFETs) were fabricated with these compounds as organic semiconductors, and their semiconducting properties were evaluated. OFETs with syn-DBBDF and syn-DNBDF showed typical p-type characteristics with hole mobilities of <1.5 × 10−3 cm2·V−1·s−1 and <1.0 × 10−1 cm2·V−1·s−1, respectively.

scholarly journals Exploring the Critical Thickness of Organic Semiconductor Layer for Enhanced Piezoresistive Sensitivity in Field-Effect Transistor Sensors

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1583 ◽  
Author(s):  
Damien Thuau ◽  
Katherine Begley ◽  
Rishat Dilmurat ◽  
Abduleziz Ablat ◽  
Guillaume Wantz ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Organic Semiconductor ◽  
Field Effect ◽  
High Performance ◽  
Critical Thickness ◽  
Field Effect Transistors ◽  
Mechanical Strain ◽  
Semiconductor Layer ◽  
Organic Field Effect Transistors ◽  
P Type

Organic semiconductors (OSCs) are promising transducer materials when applied in organic field-effect transistors (OFETs) taking advantage of their electrical properties which highly depend on the morphology of the semiconducting film. In this work, the effects of OSC thickness (ranging from 5 to 15 nm) on the piezoresistive sensitivity of a high-performance p-type organic semiconductor, namely dinaphtho [2,3-b:2,3-f] thieno [3,2–b] thiophene (DNTT), were investigated. Critical thickness of 6 nm thin film DNTT, thickness corresponding to the appearance of charge carrier percolation paths in the material, was demonstrated to be highly sensitive to mechanical strain. Gauge factors (GFs) of 42 ± 5 and −31 ± 6 were measured from the variation of output currents of 6 nm thick DNTT-based OFETs engineered on top of polymer cantilevers in response to compressive and tensile strain, respectively. The relationship between the morphologies of the different thin films and their corresponding piezoresistive sensitivities was discussed.

Interfacial Effects of UV-Ozone Treated Sol-Gel Processable ZnO for Hybrid Photodetectors and Thin Film Transistors

MRS Advances ◽  
2019 ◽  
Vol 4 (31-32) ◽  
pp. 1793-1800 ◽  
Author(s):  
Alec Pickett ◽  
Aiswarya A. Mohapatra ◽  
Suman Ray ◽  
Christopher Robledo ◽  
Kartik Ghosh ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
Sol Gel ◽  
High Mobility ◽  
Inorganic Materials ◽  
Zno Films ◽  
Type Semiconductor ◽  
Order Of Magnitude ◽  
Organic Photodetectors ◽  
Uv Ozone

ABSTRACTHybrid organic-inorganic semiconducting interfaces have attracted attention in photodiodes and field-effect transistors (FETs) due to the realization of intrinsic p-n junctions and their mechanical flexibility. With the difficulty of developing high-mobility n-type organic semiconductors due to the necessity of low LUMO levels and ambient environment stability, solution processable inorganic materials are an excellent alternative. ZnO is an intrinsic n-type semiconductor which is non-toxic and sol-gel processable, creating avenues for film patterning and fully solution processed devices. We report the improvement of electron mobilities in ZnO FETs through simple UV-Ozone processing which reduces lattice defects within the film and at the SiO2/ZnO interface. Treated ZnO films yield electron mobilities close to 10-2 cm2/Vs and on/off current ratios of 104 while non-treated films have mobilities on the order of 10-5 cm2/Vs and an order of magnitude lower on/off current ratios. Treated films also yield improved photoresponsivity and detectivity in hybrid ZnO-organic photodetectors.

scholarly journals Solution-Processed Organic and ZnO Field-Effect Transistors in Complementary Circuits

2021 ◽  
Vol 2 (2) ◽  
pp. 60-71
Author(s):  
John Barron ◽  
Alec Pickett ◽  
James Glaser ◽  
Suchismita Guha
Keyword(s):  
Field Effect ◽  
Vinylidene Fluoride ◽  
Field Effect Transistors ◽  
Sol Gel ◽  
Semiconductor Layer ◽  
Zno Films ◽  
Operating Voltage ◽  
Solution Processed ◽  
P Type ◽  
Uv Ozone

The use of high κ dielectrics lowers the operating voltage in organic field-effect transistors (FETs). Polymer ferroelectrics open the path not just for high κ values but allow processing of the dielectric films via electrical poling. Poled ferroelectric dielectrics in p-type organic FETs was seen to improve carrier mobility and reduce leakage current when compared to unpoled devices using the same dielectric. For n-type FETs, solution-processed ZnO films provide a viable low-cost option. UV–ozone-treated ZnO films was seen to improve the FET performance due to the filling of oxygen vacancies. P-type FETs were fabricated using the ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) as the dielectric along with a donor–acceptor polymer based on diketopyrrolopyrrole (DPP-DTT) as the semiconductor layer. The DPP-DTT FETs yield carrier mobilities upwards of 0.4 cm2/Vs and high on/off ratios when the PVDF-TrFE layer is electrically poled. For n-type FETs, UV–ozone-treated sol–gel ZnO films on SiO2 yield carrier mobilities of 10−2 cm2/Vs. DPP-DTT-based p- and ZnO-based n-type FETs were used in a complementary voltage inverter circuit, showing promising characteristic gain. A basic inverter model was used to simulate the inverter characteristics, using parameters from the individual FET characteristics.

scholarly journals Carbonyl-Terminated Quinoidal Oligothiophenes as p-Type Organic Semiconductors

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3020
Author(s):  
Takato Asoh ◽  
Kohsuke Kawabata ◽  
Kazuo Takimiya
Keyword(s):  
Organic Semiconductors ◽  
Field Effect Transistors ◽  
Theoretical Calculations ◽  
Energy Levels ◽  
Hole Mobility ◽  
Hole Transport ◽  
Large Contribution ◽  
Theoretical Predictions ◽  
Reorganization Energies ◽  
P Type

A series of quinoidal oligothiophenes terminated with carbonyl groups (nTDs, n = 2–4) are studied as p-type organic semiconductors for the active materials in organic field-effect transistors (OFETs) both by the theoretical and experimental approaches. The theoretical calculations clearly show their high-lying highest occupied molecular orbital (HOMO) energy levels (EHOMOs), small reorganization energies for hole transport (λholes), and large contribution of sulfur atoms to HOMOs, all of which are desirable for p-type organic semiconductors. Thus, we synthesized nTDs from the corresponding aromatic oligothiophene precursors and then evaluated their physicochemical properties and structural properties. These experimental evaluations of nTDs nicely proved the theoretical predictions, and the largest 4TDs in the series (4,4′′′-dihexyl- and 3′,4,4″,4′′′-tetrahexyl-5H,5′′′H-[2,2′:5′,2″:5″,2′′′-quaterthiophene]-5,5′′′-dione) can afford solution-processed OFETs showing unipolar p-type behaviors and hole mobility as high as 0.026 cm2 V−1 s−1.

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