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

CubeSat Structures Competition Opens Space Design to Students of the World December 16th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Error-free into the quantum computer age December 15th, 2017

Leti Will Demonstrate First 3D Anti-Crash Solution for Embedding in Drones: Fitted on a Mass-Market Microcontroller, 360Fusion Software Technology Detects any Dynamic Obstacle and Helps Guide Drones Away from Collisions December 15th, 2017

Imaging

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

JPK Instruments announce partnership with Swiss company, Cytosurge AG. The partnership makes Cytosurge’s FluidFM® technology available on the JPK NanoWizard® AFM platform December 8th, 2017

Researchers advance technique to detect ovarian cancer: Rice, MD Anderson use fluorescent carbon nanotube probes to achieve first in vivo success November 30th, 2017

Deben reports on a new publication from scientists at La Trobe University in Australia where their CT500 stage is used in micro scanning tomography experiments to better understand ceramic matrix composites under load November 29th, 2017

JPK reports on the exciting research in the School of Medicine at Sungkyunkwan University (SKKU), Suwon, South Korea using the NanoWizard® ULTRA Speed AFM to understand the binding of transcription factor Sox2 with super enhancers November 23rd, 2017

Flexible Electronics

Printing Flexible Graphene Supercapacitors December 1st, 2017

Tungsten offers nano-interconnects a path of least resistance: Crystalline tungsten shows insight and promise in addressing the challenges of electrical interconnects that have high resistivity at the nanoscale October 4th, 2017

Thin films

MIPT scientists revisit optical constants of ultrathin gold films October 20th, 2017

Rice University chemists make laser-induced graphene from wood July 31st, 2017

Graduate Students from Across the Country Attend Hands-on NanoCamp: Prominent scientists Warren Oliver, Ph.D., and George Pharr, Ph.D., presented a weeklong NanoCamp for hand-picked graduate students across the United States July 26th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Synthetic protein packages its own genetic material and evolves computationally designed protein assemblies are advancing research in synthetic life and in targeted drug delivery December 15th, 2017

Sandia researchers make solid ground toward better lithium-ion battery interfaces: Reducing the traffic jam in batteries December 13th, 2017

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Chip Technology

Error-free into the quantum computer age December 15th, 2017

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

UCLA chemists synthesize narrow ribbons of graphene using only light and heat: Tiny structures could be next-generation solution for smaller electronic devices December 8th, 2017

Device makes power conversion more efficient: New design could dramatically cut energy waste in electric vehicles, data centers, and the power grid December 8th, 2017

Self Assembly

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Nanotubes that build themselves April 14th, 2017

Nanocages for gold particles: what is happening inside? March 16th, 2017

Announcements

CubeSat Structures Competition Opens Space Design to Students of the World December 16th, 2017

Record high photoconductivity for new metal-organic framework material December 15th, 2017

Error-free into the quantum computer age December 15th, 2017

Leti Will Demonstrate First 3D Anti-Crash Solution for Embedding in Drones: Fitted on a Mass-Market Microcontroller, 360Fusion Software Technology Detects any Dynamic Obstacle and Helps Guide Drones Away from Collisions December 15th, 2017

Tools

Perking up and crimping the 'bristles' of polyelectrolyte brushes December 13th, 2017

Untangling DNA: Researchers filter the entropy out of nanopore measurements December 8th, 2017

JPK Instruments announce partnership with Swiss company, Cytosurge AG. The partnership makes Cytosurge’s FluidFM® technology available on the JPK NanoWizard® AFM platform December 8th, 2017

Researchers advance technique to detect ovarian cancer: Rice, MD Anderson use fluorescent carbon nanotube probes to achieve first in vivo success November 30th, 2017

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project