Dynamic Infrared Electro-optic Response of Soluble Organic Semiconductors in Thin Film Transistors

ABSTRACTWe use a frequency-dependent electro-optic technique to measure the hole mobility in small molecule organic semiconductors, such as 6,13 bis(triisopropylsilylethynyl)-pentacene. Measurements are made on semiconductor films in bottom gate, bottom contact field-effect transistors (FETs.) Because of the buried metal layer effect the maximum response, due to absorption in the charge layer, will be for a dielectric film ∼ 1/4 of a wavelength (in the dielectric) (e.g. ∼ 1 micron thick in the infrared.) Results are presented for FETs prepared with both spin-cast polymer and alumina dielectrics prepared by atomic layer deposition. At low frequencies the results are fit to solutions to a non-linear differential equation describing the spatial dependence of flowing charge in the FET channel, which allows us to study multiple crystals forming across one set of drain-source contacts. FETs prepared on alumina dielectrics show interesting deviations from the model at high frequencies, possibly due to increased contact impedance.

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Field Effect Transistor with ZnS Active Layer on ITO/Glass Substrate

Materials Science Forum ◽

10.4028/www.scientific.net/msf.544-545.753 ◽

2007 ◽

Vol 544-545 ◽

pp. 753-756

Author(s):

In Jae Back ◽

Su Cheol Gong ◽

Hun Seoung Lim ◽

Ik Sub Shin ◽

Seoung Woo Kuk ◽

...

Keyword(s):

Active Layer ◽

Glass Substrate ◽

Field Effect ◽

Field Effect Transistors ◽

Atomic Layer ◽

Gate Insulator ◽

Semiconductor Films ◽

Insulation Property ◽

Ito Glass ◽

Lower Mobility

The organic-inorganic field effect transistors (OIFETs) with ZnS active layer were fabricated on the ITO/glass substrate using cross-linked PVP (poly-4-vinylphenol) as a gate insulator. ZnS semiconductor films were prepared by the atomic layer deposition method. In the case of cross-linked PVP film, the leakage current and capacitance were about 1× 10-8 A and 12 nF/cm2, showing good gate insulation property. The carrier concentration and mobility of ZnS film deposited on SiO2/Si wafer was found to be -9.4×1015 cm-3 and 49.0 cm2/ V·sec, respectively. For the OIFET devices with ITO/PVP/ZnS/Ti:Au structure, the carrier mobility was about 1.9 cm2/V·sec. From the AFM images, lower mobility in the OIFET device compared with ZnS film on SiO2/Si substrate may be attributed to a rough surface morphology of ZnS film.

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Naphtho[2,1-b:3,4-b′]bisthieno[3,2-b][1]benzothiophene-based semiconductors for organic field-effect transistors

Journal of Materials Chemistry C ◽

10.1039/c5tc00631g ◽

2015 ◽

Vol 3 (31) ◽

pp. 8024-8029 ◽

Cited By ~ 7

Author(s):

Zhaoguang Li ◽

Ji Zhang ◽

Kai Zhang ◽

Weifeng Zhang ◽

Lei Guo ◽

...

Keyword(s):

Organic Semiconductors ◽

Field Effect ◽

High Performance ◽

Field Effect Transistors ◽

Hole Mobility ◽

Building Blocks ◽

Organic Field Effect Transistors ◽

Next Generation

Naphtho[2,1-b:3,4-b′]bisthieno[3,2-b][1]benzothiophene derivatives exhibiting a hole mobility of up to 0.25 cm2 V−1 s−1 show promise as useful building blocks to construct next-generation high performance organic semiconductors.

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Naphthalene flanked diketopyrrolopyrrole based organic semiconductors for high performance organic field effect transistors

New Journal of Chemistry ◽

10.1039/c8nj01453a ◽

2018 ◽

Vol 42 (15) ◽

pp. 12374-12385 ◽

Cited By ~ 14

Author(s):

Qian Liu ◽

Huabin Sun ◽

Chula Blaikie ◽

Chiara Caporale ◽

Sergei Manzhos ◽

...

Keyword(s):

Organic Semiconductors ◽

Field Effect ◽

High Performance ◽

Field Effect Transistors ◽

Hole Mobility ◽

Organic Field Effect Transistors

A newly reported alkylated naphthalene flanked DPP monomers without any further functionalization show high hole mobility in OFET devices.

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Carbonyl-Terminated Quinoidal Oligothiophenes as p-Type Organic Semiconductors

Materials ◽

10.3390/ma13133020 ◽

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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Greater than 10 cm 2 V −1 s −1 : A breakthrough of organic semiconductors for field‐effect transistors

InfoMat ◽

10.1002/inf2.12188 ◽

2021 ◽

Author(s):

Peng Hu ◽

Xuexia He ◽

Hui Jiang

Keyword(s):

Organic Semiconductors ◽

Field Effect ◽

Field Effect Transistors

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Atomic Layer Deposition (ALD) of Metal Gates for CMOS

Applied Sciences ◽

10.3390/app9112388 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2388 ◽

Cited By ~ 2

Author(s):

Chao Zhao ◽

Jinjuan Xiang

Keyword(s):

Atomic Layer Deposition ◽

Field Effect Transistors ◽

Material Selection ◽

Atomic Layer ◽

Oxide Semiconductor ◽

Metal Gate ◽

Gate Stack ◽

Short Channel ◽

Metal Gates ◽

Layer Deposition

The continuous down-scaling of complementary metal oxide semiconductor (CMOS) field effect transistors (FETs) had been suffering two fateful technical issues, one relative to the thinning of gate dielectric and the other to the aggressive shortening of channel in last 20 years. To solve the first issue, the high-κ dielectric and metal gate technology had been induced to replace the conventional gate stack of silicon dioxide layer and poly-silicon. To suppress the short channel effects, device architecture had changed from planar bulk Si device to fully depleted silicon on insulator (FDSOI) and FinFETs, and will transit to gate all-around FETs (GAA-FETs). Different from the planar devices, the FinFETs and GAA-FETs have a 3D channel. The conventional high-κ/metal gate process using sputtering faces conformality difficulty, and all atomic layer deposition (ALD) of gate stack become necessary. This review covers both scientific and technological parts related to the ALD of metal gates including the concept of effect work function, the material selection, the precursors for the deposition, the threshold voltage (Vt) tuning of the metal gate in contact with HfO2/SiO2/Si. The ALD of n-type metal gate will be detailed systematically, based mainly on the authors’ works in last five years, and the all ALD gate stacks will be proposed for the future generations based on the learning.

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Hole mobility enhancement of pentacene organic field-effect transistors using 4,4′,4″-tris[3-methylphenyl(phenyl)amino] triphenylamine as a hole injection interlayer

Applied Physics Letters ◽

10.1063/1.3624586 ◽

2011 ◽

Vol 99 (6) ◽

pp. 063306 ◽

Cited By ~ 37

Keyword(s):

Field Effect ◽

Field Effect Transistors ◽

Hole Mobility ◽

Hole Injection ◽

Organic Field Effect Transistors

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Incorporation of pyrrole to oligothiophene-based quinoids endcapped with dicyanomethylene: a new class of solution processable n-channel organic semiconductors for air-stable organic field-effect transistors

Journal of Materials Chemistry ◽

10.1039/c2jm16700j ◽

2012 ◽

Vol 22 (12) ◽

pp. 5706 ◽

Cited By ~ 26

Author(s):

Yali Qiao ◽

Jing Zhang ◽

Wei Xu ◽

Daoben Zhu

Keyword(s):

Organic Semiconductors ◽

Field Effect ◽

Field Effect Transistors ◽

Organic Field Effect Transistors ◽

New Class ◽

Solution Processable

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Comparative Study ofSiO2,Al2O3, and BeO Ultrathin Interfacial Barrier Layers in Si Metal-Oxide-Semiconductor Devices

Active and Passive Electronic Components ◽

10.1155/2012/359580 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

J. H. Yum ◽

J. Oh ◽

Todd. W. Hudnall ◽

C. W. Bielawski ◽

G. Bersuker ◽

...

Keyword(s):

Metal Oxide ◽

High Performance ◽

Field Effect Transistors ◽

Beryllium Oxide ◽

Atomic Layer ◽

Oxide Thickness ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Flat Band ◽

Effective Electron

In a previous study, we have demonstrated that beryllium oxide (BeO) film grown by atomic layer deposition (ALD) on Si and III-V MOS devices has excellent electrical and physical characteristics. In this paper, we compare the electrical characteristics of inserting an ultrathin interfacial barrier layer such as SiO2, Al2O3, or BeO between the HfO2gate dielectric and Si substrate in metal oxide semiconductor capacitors (MOSCAPs) and n-channel inversion type metal oxide semiconductor field effect transistors (MOSFETs). Si MOSCAPs and MOSFETs with a BeO/HfO2gate stack exhibited high performance and reliability characteristics, including a 34% improvement in drive current, slightly better reduction in subthreshold swing, 42% increase in effective electron mobility at an electric field of 1 MV/cm, slightly low equivalent oxide thickness, less stress-induced flat-band voltage shift, less stress induced leakage current, and less interface charge.

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