scholarly journals Processing–Structure–Performance Relationship in Organic Transistors: Experiments and Model

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 197
Author(s):  
Rosalba Liguori ◽  
Antonio Facchetti ◽  
Gian Domenico Licciardo ◽  
Luigi Di Benedetto
Keyword(s):  
Charge Trapping ◽  
Organic Transistors ◽  
Organic Thin Film ◽  
Metal Contacts ◽  
Dispersive Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Mobile Ions ◽  
Physical Phenomena

In this paper, organic thin film transistors with different configurations are fabricated, and the effect on their performance when tailoring the semiconductor/insulator and semiconductor/contact interfaces through suitable treatments is analyzed. It is shown that the admittance spectroscopy used together with a properly developed electrical model turns out to be a particularly appropriate technique for correlating the performance of devices based on new materials in the manufacturing methods. The model proposed here to describe the equivalent metal–insulator–semiconductor (MIS) capacitor enables the extraction of a wide range of parameters and the study of the physical phenomena occurring in the transistors: diffusion of mobile ions through the insulator, charge trapping at the interfaces, dispersive transport in the semiconductor, and charge injection at the metal contacts. This is necessary to improve performance and stability in the case, like this one, of a novel organic semiconductor being employed. Atomic force microscopy images are also exploited to support the relationship between the semiconductor morphology and the electrical parameters.

Studies of Nanomechanical Properties of Pulsed Laser Deposited NbN films on Si Using Nanoindentation

2012 ◽  
Vol 1424 ◽  
Author(s):  
M. A. Mamun ◽  
A. H. Farha ◽  
Y. Ufuktepe ◽  
H. E. Elsayed-Ali ◽  
A. A. Elmustafa
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
Niobium Nitride ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Pile Up ◽  
Average Modulus

ABSTRACTNanomechanical and structural properties of pulsed laser deposited niobium nitride thin films were investigated using X-ray diffraction, atomic force microscopy, and nanoindentation. NbN film reveals cubic δ-NbN structure with the corresponding diffraction peaks from the (111), (200), and (220) planes. The NbN thin films depict highly granular structure, with a wide range of grain sizes that range from 15-40 nm with an average surface roughness of 6 nm. The average modulus of the film is 420±60 GPa, whereas for the substrate the average modulus is 180 GPa, which is considered higher than the average modulus for Si reported in the literature due to pile-up. The hardness of the film increases from an average of 12 GPa for deep indents (Si substrate) measured using XP CSM and load control (LC) modes to an average of 25 GPa measured using the DCM II head in CSM and LC modules. The average hardness of the Si substrate is 12 GPa.

scholarly journals Nucleation and Growth of Supported Metal Clusters at Defect Sites on Mgo and NaCl (001) Surfaces: The Cases of Pd and Ag

1999 ◽  
Vol 570 ◽  
Author(s):  
J. A. Venables ◽  
G. Haas ◽  
H. Brune ◽  
J.H. Harding
Keyword(s):  
Deposition Temperature ◽  
Metal Clusters ◽  
Variable Temperature ◽  
Nucleation And Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Defect Sites ◽  
Wide Range ◽  
Adsorption Surface

ABSTRACTNucleation and growth of metal clusters at defect sites is discussed in terms of rate equation models, which are applied to the cases of Pd and Ag on MgO(001) and NaCl(001) surfaces. Pd/MgO has been studied experimentally by variable temperature atomic force microscopy (AFM). The island density of Pd on Ar-cleaved surfaces was determined in-situ by AFM for a wide range of deposition temperature and flux, and stays constant over a remarkably wide range of parameters; for a particular flux, this plateau extends from 200 K ≤ T ≤ 600 K, but at higher temperatures the density decreases. The range of energies for defect trapping, adsorption, surface diffusion and pair binding are deduced, and compared with earlier data for Ag on NaCl, and with recent calculations for these metals on both NaCl and MgO

Sensor Egregium – An Atomic Force Microscope Sensor for Continuously Variable Resonance Amplification

2021 ◽  
pp. 1-23
Author(s):  
Rafiul Shihab ◽  
Tasmirul Jalil ◽  
Burak Gulsacan ◽  
Matteo Aureli ◽  
Ryan Tung
Keyword(s):  
Finite Element Analysis ◽  
Atomic Force Microscope ◽  
Natural Frequencies ◽  
Proof Of Concept ◽  
Element Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Curve Veering ◽  
Dynamic Phenomena

Abstract Numerous nanometrology techniques concerned with probing a wide range of frequency dependent properties would benefit from a cantilevered sensor with tunable natural frequencies. In this work, we propose a method to arbitrarily tune the stiffness and natural frequencies of a microplate sensor for atomic force microscope applications, thereby allowing resonance amplification at a broad range of frequencies. This method is predicated on the principle of curvature-based stiffening. A macroscale experiment is conducted to verify the feasibility of the method. Next, a microscale finite element analysis is conducted on a proof-of-concept device. We show that both the stiffness and various natural frequencies of the device can be highly controlled through applied transverse curvature. Dynamic phenomena encountered in the method, such as eigenvalue curve veering, are discussed and methods are presented to accommodate these phenomena. We believe that this study will facilitate the development of future curvature-based microscale sensors for atomic force microscopy applications.

scholarly journals Towards an Understanding of Crystallization by Attachment

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 463
Author(s):  
Haihua Pan ◽  
Ruikang Tang
Keyword(s):  
Capillary Condensation ◽  
Force Measurements ◽  
Force Microscopy ◽  
Physical Conditions ◽  
Driving Mechanisms ◽  
Atomic Force ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Hydration Layers

Crystallization via particle attachment was used in a unified model for both classical and non-classical crystallization pathways, which have been widely observed in biomimetic mineralization and geological fields. However, much remains unknown about the detailed processes and driving mechanisms for the attachment. Here, we take calcite crystal as a model mineral to investigate the detailed attachment process using in situ Atomic Force Microscopy (AFM) force measurements and molecular dynamics simulations. The results show that hydration layers hinder the attachment; however, in supersaturated solutions, ionic bridges are formed between crystal gaps as a result of capillary condensation, which might enhance the aggregation of calcite crystals. These findings provide a more detailed understanding of the crystal attachment, which is of vital importance for a better understanding of mineral formation under biological and geological environments with a wide range of chemical and physical conditions.

scholarly journals Heated-Tip AFM: Applications in Nanocomposite Polymer Membranes and Energetic Materials

2007 ◽  
Vol 15 (1) ◽  
pp. 20-25
Author(s):  
Jason P. Killgore ◽  
William King ◽  
Kevin Kjoller ◽  
René M. Overney
Keyword(s):  
Data Storage ◽  
Energetic Materials ◽  
Measurement Capability ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanocomposite Polymer ◽  
Wide Range ◽  
Measurement And Analysis ◽  
Nanoscale Topography ◽  
Temperature Controlled

Atomic Force Microscopy (AFM) is a key technique for the measurement and analysis of samples when nanoscale topography is of interest. It offers a number of complementary probing modes that extend an AFM's measurement capability to a wide range of material and transport properties of surfaces, including hardness, friction, conductivity and adhesion among others. Sample temperature controlled AFM extends the study of surface morphology and properties to include changes in the material phases.Recently, silicon microfabricated AFM cantilevers that have integrated heaters, as shown in figure 1, have become commercially available. These cantilevers were initially developed for probe based data storage by researchers at IBM Zurich, Figure 1. With the availability of these cantilevers, AFM measurements can be performed where the tip is heated as opposed to the sample.

scholarly journals Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

2016 ◽  
Vol 108 (24) ◽  
pp. 243101 ◽  
Author(s):  
Aymeric Vecchiola ◽  
Pascal Chrétien ◽  
Sophie Delprat ◽  
Karim Bouzehouane ◽  
Olivier Schneegans ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Local Resistance ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Wide Range ◽  
Intermittent Contact

scholarly journals Morphology of Ethylene/1-Octene Copolymers and Their Blends with High Density Polythylene: A Microscopic Evaluation

2013 ◽  
Vol 30 ◽  
pp. 5-12 ◽  
Author(s):  
Rameshwar Adhikari
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Chemical Society ◽  
High Density ◽  
Force Microscopy ◽  
Strain Behavior ◽  
Atomic Force ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Wide Range

The investigation into morphology formation in ethylene/1-octene copolymers (EOCs) comprising variable 1-octene content and their blends with high density polyethylene (HDPE) and hence their tensile mechanical properties have been reported. The morphological analysis by means of atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed the macrophase separation of the components in the blends. In contrast to well defined spherulitic morphology and lamellar structure of the HDPE, the EOCs exhibited progressively distorted lamellar morphology with increasing 1-octene content. At high 1-octene content, the EOC samples possessed the ‘worm-like’ crystals, which resemble the ‘fringed micelles’ discussed in the literature. The blends allow a balance of mechanical properties (stiffness and toughness) over a wide range as shown by tensile stress strain behavior of the blends.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9329Journal of Nepal Chemical Society Vol. 30, 2012 Page: 5-12 Uploaded date: 12/16/2013 

Atomic force microscopy: seeing molecules of lipid and immunoglobulin

1991 ◽  
Vol 37 (9) ◽  
pp. 1497-1501 ◽  
Author(s):  
H G Hansma ◽  
A L Weisenhorn ◽  
A B Edmundson ◽  
H E Gaub ◽  
P K Hansma
Keyword(s):  
Immunoglobulin M ◽  
Biological Molecules ◽  
Ammonium Bromide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Head Groups ◽  
Afm Imaging ◽  
Wide Range ◽  
Lipid Films ◽  
Active Imaging

Abstract The atomic force microscope (AFM) can image individual molecules by raster-scanning a sharp tip over a surface. In this paper we present molecular-resolution images of immunoglobulin M (IgM) and of ultraviolet light-polymerized films of the lipid dimethyl-bis(pentacosadiynoyloxyethyl) ammonium bromide ("BRONCO"). The polar head groups of individual lipid molecules can be resolved on the surface of this and other lipid films. These lipid films also provide a good substrate for AFM imaging of DNA and of other molecules such as antibodies. Because the AFM scans surfaces, it is most often successful at imaging either molecules that can form an array on a surface or molecules that are quite firmly attached to a surface. The ability of the AFM to operate under water, buffers, and other liquids makes it possible to study biological molecules under conditions in which they are physiologically active. Imaging of the actual molecular process of fibrin polymerization shows the potential of the AFM for studying biological processes. In the six years since its invention, the AFM has excited much interest and has imaged molecules in a wide range of systems.

scholarly journals Optimizing Pentacene Growth in Low-Voltage Organic Thin-Film Transistors Prepared by Dry Fabrication Techniques

2012 ◽  
Vol 1435 ◽  
Author(s):  
S. Gupta ◽  
K. C. Chinnam ◽  
M. Zelzer ◽  
R. Ulijn ◽  
H. Gleskova
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Field Effect ◽  
Evaporation Rate ◽  
Low Voltage ◽  
Organic Thin Film Transistors ◽  
Organic Thin Film ◽  
Transistor Channel ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTWe have studied the effect of pentacene purity and evaporation rate on low-voltage organic thin-film transistors (OTFTs) prepared solely by dry fabrication techniques. The maximum field-effect mobility of 0.07 cm2/Vs was achieved for the highest pentacene evaporation rate of 0.32 Å/s and four-time purified pentacene. Four-time purified pentacene also led to the lowest threshold voltage of -1.1 V and inverse subthreshold slope of ∼100 mV/decade. In addition, pentacene surface was imaged using atomic force microscopy, and the transistor channel and contact resistances for various pentacene evaporation rates were extracted and compared to field-effect mobilities.

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