Related Experiment Video
Updated: Jul 11, 2026
08:43
Effect of Bending on the Electrical Characteristics of Flexible Organic Single Crystal-based Field-effect Transistors
Published on: November 7, 2016
Polymer gate dielectric surface viscoelasticity modulates pentacene transistor performance.
Choongik Kim1, Antonio Facchetti, Tobin J Marks
1Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|October 6, 2007
Summary
Polymer films show lower glass transition temperatures (Tg) when confined. Pentacene thin films on these polymers reveal distinct transitions and performance changes linked to the dielectric
Area of Science:
- Materials Science
- Polymer Science
- Organic Electronics
Background:
- Nanoscopically confined polymer films exhibit significantly depressed glass transition temperatures (Tg) compared to bulk materials.
- The behavior of organic thin-film transistors (OTFTs) is influenced by the properties of the underlying polymer dielectric.
- Understanding the interface between organic semiconductors and polymer dielectrics is crucial for device performance.
Purpose of the Study:
- To investigate the impact of polymer dielectric viscoelasticity on pentacene thin-film morphology, microstructure, and transistor performance.
- To identify specific growth temperatures where transitions occur and correlate them with dielectric chain mobility.
- To highlight the significance of buried interface effects in optimizing organic thin-film transistor (OTFT) design.
Main Methods:
- Growth of pentacene thin films on polymer gate dielectrics at controlled temperatures below the bulk Tg.
- Characterization of film morphology and microstructure using advanced techniques.
- Fabrication and electrical characterization of organic thin-film transistors (OTFTs) to assess performance.
- Analysis of current-voltage response to detect interface viscoelasticity effects.
Main Results:
- Pentacene films grown on polymer dielectrics exhibit abrupt morphological and microstructural transitions at specific growth temperatures.
- These transitions correlate with the polymer dielectric entering its rubbery state, indicating increased chain mobility.
- Organic thin-film transistor (OTFT) performance shows distinct discontinuities at these transition temperatures, independent of dielectric thickness.
- The buried interface viscoelasticity effect is detectable through analysis of the current-voltage response.
Conclusions:
- The viscoelastic state of the polymer dielectric significantly impacts the properties of overlying pentacene thin films and OTFT performance.
- Optimization of organic electronic devices requires careful consideration of the fundamental buried interface viscoelasticity.
- This effect provides a new avenue for tuning and enhancing the performance of organic thin-film transistors.
Related Concept Videos
01:31Dielectric Polarization in a Capacitor
The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...
01:27Biasing of Metal-Semiconductor Junctions
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
01:22Biasing of FET
Biasing a Junction Field Effect Transistor (JFET) is crucial for setting operational parameters and ensuring efficient functioning in electronic circuits. JFETs are characterized by using a single carrier type in N-channel or P-channel configurations, where the channel is surrounded by PN junctions. These junctions are central to the device's ability to control current flow.
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate...
In an N-channel JFET, the structure consists of N-type material forming the channel on a P-type substrate, with the gate...
01:25MOS Capacitor
A Metal-Oxide-Semiconductor (MOS) capacitor is a fundamental structure used extensively in semiconductor device technology, particularly in the fabrication of integrated circuits and MOSFETs (metal-oxide-semiconductor field-effect transistors). The MOS capacitor consists of three layers: a metal gate, a dielectric oxide, and a semiconductor substrate.
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
The metal gate is typically made from highly conductive materials such as aluminum or polysilicon. Beneath the metal gate lies a thin layer of...
01:17Characteristics of MOSFET
Metal-oxide-semiconductor field-effect Transistors, or MOSFETs, play a critical role in electronic circuits. They are primarily utilized for amplifying and switching signals.
Various vital parameters influence their functionality, which is crucial for theory and electronics applications. First, channel dimensions, precisely length, and width, are pivotal. The size of these channels affects the transistor's ability to carry current and switching speeds; shorter channels typically enable quicker...
Various vital parameters influence their functionality, which is crucial for theory and electronics applications. First, channel dimensions, precisely length, and width, are pivotal. The size of these channels affects the transistor's ability to carry current and switching speeds; shorter channels typically enable quicker...
01:16Biasing of P-N Junction
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...