Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > CHESS X-rays help characterize organic transistors

Advanced Materials
The cover image shows the X-ray microbeam footprint on the gate electrode of an organic transistor and scattered X-ray beams emanating from the molecular film.
Advanced Materials

The cover image shows the X-ray microbeam footprint on the gate electrode of an organic transistor and scattered X-ray beams emanating from the molecular film.

Abstract:
Plastic electronics, in which an organic material replaces silicon, hold promise for low-cost, flexible electronics. But understanding and controlling these materials' microstructures is an ongoing challenge.

CHESS X-rays help characterize organic transistors

Ithaca, NY | Posted on November 20th, 2012

With the help of the D1 X-ray beamline at the Cornell High Energy Synchrotron Source (CHESS), scientists have come many steps closer to designing the perfect organic semiconductor by spatially mapping the microstructure, texture, grain sizes and grain orientations of organic semiconductor thin films.

Detlef Smilgies, senior research associate at CHESS, is co-author of an article in the Nov. 2 issue of the journal Advanced Materials (Vol. 24, No. 41), featured on the journal's cover, that describes this direct structural mapping.

The study's senior author, Aram Amassian of King Abdullah University of Science and Technology (KAUST), is a former Cornell postdoctoral associate, and the first author, Amassian's research associate Ruipeng Li, is a former visiting graduate student at CHESS; both are frequent Cornell synchrotron users.

The performance of a transistor is usually described by the mobility of its charge carriers -- the quicker the charge carriers can move through the material, the better. Charge mobility can be hampered by grain boundaries, which are the interfaces of individual grains in a crystal, either because they are misaligned or growing on different planes.

These interfaces play an important role in the texture of the crystalline organic material. A basic transistor typically has a source, where charge carriers enter; a drain, where the charge carriers exit; and a gate in the middle, which regulates the mobility of the charge carriers. In the most common architecture, the organic semiconductor is printed on a substrate pre-patterned with source and drain electrodes. The organic layer can thus form different growth planes on different parts of the substrate, and it's hard to tell fundamentally which growth planes are best to carry charges.

To shed some light on this question, the researchers used a technique called microbeam grazing incidence wide-angle X-ray scattering to probe how the organic transistor's molecular structure changed within the gate channel of the transistor, i.e., between the source and the drain electrodes. The microbeam at CHESS D1 station was obtained with an X-ray-focusing capillary -- an optical device that helps narrow the X-ray beam -- only 10 microns wide or one-fifth the width of a human hair.

This microbeam intercepted the transistors at a low angle of 2 degrees; the resulting wide-angle scattered X-rays were collected with a high-resolution camera. The scientists found that a particular growth plane that formed on the gold electrode extended up to tens of microns into the channel. Then a mix of planes occurred in the center of the channel.

When the channel width was below 20 microns, a favorable orientation prevailed, and the devices had good performance, while wider channels with mixed structures performed more poorly, with lower carrier mobility.

A chemical modification of the electrode surfaces with a fluorinated self-assembled monolayer was found to promote the formation of the favorable growth plane, which extended well into the channel. In some cases this growth plane bridged the channel entirely, significantly reducing the bottlenecks to charge transport of the untreated device.

Smilgies developed the instrumentation used in the experiment and helped with calibration and characterization of the microbeam used in the study. D1, he noted, is especially suited for in-situ studies of soft materials -- techniques that Smilgies has developed over the past 12 years at CHESS.

Oana Jurchescu and her student Jeremy Ward at Wake Forest University supplied the devices; John Anthony and Marcia Payne at the University of Kentucky provided the molecular material. CHESS is supported by the National Science Foundation and National Institutes of Health. The study was also supported by the KAUST Office of Competitive Research Funds, which funds part of the D1 beamline instrumentation.

####

For more information, please click here

Contacts:
Media Contact:
Syl Kacapyr
(607) 255-7701


Cornell Chronicle:
Anne Ju
(607) 255-9735

Copyright © Cornell University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication July 13th, 2018

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Oxford Instruments’ 22 Tesla superconducting magnet system commissioned at the UAM, making it the most intense magnetic field available outside a large international facility July 12th, 2018

Nanometrics to Announce Second Quarter Financial Results on July 31, 2018 July 12th, 2018

Imaging

Oxford Instruments’ 22 Tesla superconducting magnet system commissioned at the UAM, making it the most intense magnetic field available outside a large international facility July 12th, 2018

Alzheimer's breakthrough: Brain metals that may drive disease progression revealed: In brains affected by Alzheimer's, researchers identify chemically reduced iron species, with mineral forms including a magnetic iron oxide June 22nd, 2018

Thin films

New optical sensor can determine if molecules are left or right 'handed' June 13th, 2018

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

High efficiency solar power conversion allowed by a novel composite material: A composite thin film developed at INRS improves significantly solar cells' power conversion efficiency April 10th, 2018

Researchers develop nanoparticle films for high-density data storage: April 3rd, 2018

Flexible Electronics

Strain improves performance of atomically thin semiconductor material May 11th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication July 13th, 2018

Carbon is the new black: Researchers use carbon nanotubes to develop clothing that can double as batteries July 10th, 2018

High-power electronics keep their cool with new heat-conducting crystals July 6th, 2018

Chip Technology

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Nanometrics to Announce Second Quarter Financial Results on July 31, 2018 July 12th, 2018

Leti and Soitec Launch a New Substrate Innovation Center to Develop Engineered Substrate Solutions: Industry-inclusive hub promotes early collaboration and learning from substrate to system level July 11th, 2018

GLOBALFOUNDRIES Surpasses $2 Billion in Design Win Revenue on 22FDX® Technology : With 50 client designs and growing, 22FDX proves its value as a cost-effective solution for power-sensitive applications July 9th, 2018

Self Assembly

DNA drives design principles for lighter, thinner optical displays: Lighter gold nanoparticles could replace thicker, heavier layered polymers used in displays’ back-reflectors June 27th, 2018

Collaboration yields discovery of 12-sided silica cages June 20th, 2018

Self-assembling 3D battery would charge in seconds May 22nd, 2018

Engineered polymer membranes could be new option for water treatment May 6th, 2018

Announcements

Tuning into quantum: Scientists unlock signal frequency control of precision atom qubits July 16th, 2018

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication July 13th, 2018

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides July 13th, 2018

Tools

Oxford Instruments’ 22 Tesla superconducting magnet system commissioned at the UAM, making it the most intense magnetic field available outside a large international facility July 12th, 2018

Nanometrics to Announce Second Quarter Financial Results on July 31, 2018 July 12th, 2018

Nanometrics to Participate in the 10th Annual CEO Investor Summit 2018: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2018 in San Francisco June 28th, 2018

The Institute of Applied Physics at the University of Tsukuba near Tokyo in Japan uses Deben's ARM2 detector to better understand catalytic reaction mechanisms June 27th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project