Penetration of Mg:Ag electrode fabricated by facing-target sputtering into the organic semiconductor layer

Organic semiconducting material based sensors have been used for various environmental applications. Organic field effect transistors (OFETs) also find their applications in explosive vapor detection and total ionizing radiation dose determination. OFETs using poly 3-hexylthiophene (P3HT), a p-type organic semiconductor material and CuII tetraphenylporphyrin ( CuTPP ) composite as their active material were investigated as sensors for detection of various nitro-based explosive vapors with greater than parts per billion sensitivity range. Significant changes, suitable for sensor response, were observed in ON current (Ion) and transconductance (gm) extracted from electrical characteristics of the OFET after exposure to vapors of various explosive compounds. However, a similar device response was not observed to strong oxidizing agents such as benzoquinone (BQ) and benzophenone (BP). Also, the use of organic semiconducting material sensors for determining total ionizing radiation dose was studied, wherein the conductivity of the material was measured as a function of total ionizing radiation dose. An organic semiconducting material resistor was exposed to γ-radiation and it was observed that the change in resistance was proportional to the ionizing radiation dose. Changes in various parameters extracted from electrical characteristics of the OFET after γ-radiation exposure resulted in an improved sensitivity. To protect the organic semiconductor layer from the degradation in the ambient the sensors were passivated with a thin layer of silicon nitride.

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Investigation on different organic semiconductor/organic dielectric interfaces in pentacene-based thin-film transistors

MRS Proceedings ◽

10.1557/proc-1029-f02-03 ◽

2007 ◽

Vol 1029 ◽

Author(s):

Emanuele Orgiu ◽

Mohammad Taki ◽

Beatrice Fraboni ◽

Simone Locci ◽

Annalisa Bonfiglio

Keyword(s):

Thin Film ◽

Organic Semiconductor ◽

Thin Film Transistors ◽

Hole Transport ◽

Gate Insulator ◽

Semiconductor Layer ◽

Poly Vinyl Alcohol ◽

Physical Interaction ◽

Organic Thin Film ◽

Organic Dielectrics

AbstractOrganic Thin-Film Transistors (OTFTs) in top-contact configuration and Metal-Insulator-Semiconductor (MIS) structures with different organic dielectrics as the gate insulator have been fabricated using the same organic semiconductor layer, pentacene, in order to investigate the changes in the electrical behavior by varying the interface properties. A gold bottom gate electrode was sputtered on a glass substrate whereas gold source and drain were thermally evaporated onto the pentacene layer. Several organic dielectrics have been tested as insulating layers, namely were poly(vinyl alcohol) (PVA), polyvinyl alcohol with ammonium dichromate (PVAad) as a cross-linking agent, poly (4-vinyl phenol) (PVP), poly(dimethylsiloxane) (PDMS) and poly(methylsilsesquioxane) (pMSSQ). The interesting differences found out by varying the interface confirm that the chemical-physical interaction between semiconductor and dielectric is crucial for the conduction mechanisms of the charge carriers. In particular we observed that the electron traps can influence not only the electron transport, therefore allowing a more or less marked ambipolar behavior, but also affect the hole transport.

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Possible Deviation from the well-known Threshold Behavior of Field-Effect Doping Phenomenon in Extremely Thin Organic Semiconductor Layer

Japanese Journal of Applied Physics ◽

10.1143/jjap.43.2735 ◽

2004 ◽

Vol 43 (5A) ◽

pp. 2735-2736 ◽

Cited By ~ 3

Author(s):

Keiichi Ikegami

Keyword(s):

Organic Semiconductor ◽

Field Effect ◽

Semiconductor Layer ◽

Threshold Behavior

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

Materials ◽

10.3390/ma13071583 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1583 ◽

Cited By ~ 4

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.

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Synergistic electrodeposition of bilayer films and analysis by Raman spectroscopy

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.14.191 ◽

2018 ◽

Vol 14 ◽

pp. 2186-2189

Author(s):

Saadeldin E T Elmasly ◽

Luca Guerrini ◽

Joseph Cameron ◽

Alexander L Kanibolotsky ◽

Neil J Findlay ◽

...

Keyword(s):

Raman Spectroscopy ◽

Electrochemical Deposition ◽

Organic Semiconductor ◽

Semiconductor Layer ◽

Solution Processed ◽

Bilayer Films ◽

The Poor ◽

Electrochemically Deposited ◽

Organic Devices ◽

Subsequent Layer

A novel methodology towards fabrication of multilayer organic devices, employing electrochemical polymer growth to form PEDOT and PEDTT layers, is successfully demonstrated. Moreover, careful control of the electrochemical conditions allows the degree of doping to be effectively altered for one of the polymer layers. Raman spectroscopy confirmed the formation and doped states of the PEDOT/PEDTT bilayer. The electrochemical deposition of a bilayer containing a de-doped PEDTT layer on top of doped PEDOT is analogous to a solution-processed organic semiconductor layer deposited on top of a PEDOT:PSS layer without the acidic PSS polymer. However, the poor solubility of electrochemically deposited PEDTT (or other electropolymerised potential candidates) raises the possibility of depositing a subsequent layer via solution-processing.

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