Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Improving organic transistors that drive flexible and conformable electronics: UMass Amherst scientists advance understanding of strain effects on performance

Schematic of wrinkled rubrene single-crystal field-effect transistor. Wrinkles are obtained when in-plane compressive strain is applied on the elastomeric substrate. Electric current between gold (Au) electrodes is modulated by the deformation imposed by the wrinkles.
CREDIT: UMass Amherst
Schematic of wrinkled rubrene single-crystal field-effect transistor. Wrinkles are obtained when in-plane compressive strain is applied on the elastomeric substrate. Electric current between gold (Au) electrodes is modulated by the deformation imposed by the wrinkles.

CREDIT: UMass Amherst

Abstract:
A revolution is coming in flexible electronic technologies as cheaper, more flexible, organic transistors come on the scene to replace expensive, rigid, silicone-based semiconductors, but not enough is known about how bending in these new thin-film electronic devices will affect their performance, say materials scientists at the University of Massachusetts Amherst.

Improving organic transistors that drive flexible and conformable electronics: UMass Amherst scientists advance understanding of strain effects on performance

Amherst. MA | Posted on May 5th, 2015

Writing in the current issue of Nature Communications, polymer scientists Alejandro Briseño and Alfred Crosby at UMass Amherst, with their doctoral student Marcos Reyes-Martinez, now a postdoctoral researcher at Princeton, report results of their recent investigation of how micro-scale wrinkling affects electrical performance in carbon-based, single-crystal semiconductors.

They are the first to apply inhomogeneous deformations, that is strain, to the conducting channel of an organic transistor and to understand the observed effects, says Reyes-Martinez, who conducted the series of experiments as part of his doctoral work.

As he explains, "This is relevant to today's tech industry because transistors drive the logic of all the consumer electronics we use. In the screen on your smart phone, for example, every little pixel that makes up the image is turned on and off by hundreds of thousands or even millions of miniaturized transistors."

"Traditionally, the transistors are rigid, made of an inorganic material such as silicon," he adds. "We're working with a crystalline semiconductor called rubrene, which is an organic, carbon-based material that has performance factors, such as charge-carrier mobility, surpassing those measured in amorphous silicon. Organic semiconductors are an interesting alternative to silicon because their properties can be tuned to make them easily processed, allowing them to coat a variety of surfaces, including soft substrates at relatively low temperatures. As a result, devices based on organic semiconductors are projected to be cheaper since they do not require high temperatures, clean rooms and expensive processing steps like silicon does."

Until now, Reyes-Martinez notes, most researchers have focused on controlling the detrimental effects of mechanical deformation to a transistor's electrical properties. But in their series of systematic experiments, the UMass Amherst team discovered that mechanical deformations only decrease performance under certain conditions, and actually can enhance or have no effect in other instances.

"Our goal was not only to show these effects, but to explain and understand them. What we've done is take advantage of the ordered structure of ultra-thin organic single crystals of rubrene to fabricate high-perfomance, thin-film transistors," he says. "This is the first time that anyone has carried out detailed fundamental work at these length scales with a single crystal."

Though single crystals were once thought to be too fragile for flexible applications, the UMass Amherst team found that crystals ranging in thickness from about 150 nanometers to 1 micrometer were thin enough to be wrinkled and applied to any elastomer substrate. Reyes-Martinez also notes, "Our experiments are especially important because they help scientists working on flexible electronic devices to determine performance limitations of new materials under extreme mechanical deformations, such as when electronic devices conform to skin."

They developed an analytical model based on plate bending theory to quantify the different local strains imposed on the transistor structure by the wrinkle deformations. Using their model they are able to predict how different deformations modulate charge mobility, which no one had quantified before, Reyes-Martinez notes.

These contributions "represent a significant step forward in structure-function relationships in organic semiconductors, critical for the development of the next generation of flexible electronic devices," the authors point out.

####

For more information, please click here

Contacts:
Janet Lathrop

413-545-0444

Copyright © University of Massachusetts at Amherst

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

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Flexible Electronics

Electrons screen against conductivity-killer in organic semiconductors: The discovery is the first step towards creating effective organic semiconductors, which use significantly less water and energy, and produce far less waste than their inorganic counterparts February 16th, 2024

CityU awarded invention: Soft, ultrathin photonic material cools down wearable electronic devices June 30th, 2023

Liquid metal sticks to surfaces without a binding agent June 9th, 2023

Breaking through the limits of stretchable semiconductors with molecular brakes that harness light June 9th, 2023

Tin selenide nanosheets enables to develop wearable tracking devices December 9th, 2022

Hardware

The present and future of computing get a boost from new research July 21st, 2023

Thin films

Understanding the mechanism of non-uniform formation of diamond film on tools: Paving the way to a dry process with less environmental impact March 24th, 2023

New study introduces the best graphite films: The work by Distinguished Professor Feng Ding at UNIST has been published in the October 2022 issue of Nature Nanotechnology November 4th, 2022

Thin-film, high-frequency antenna array offers new flexibility for wireless communications November 5th, 2021

Chip Technology

New chip opens door to AI computing at light speed February 16th, 2024

HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024

Electrons screen against conductivity-killer in organic semiconductors: The discovery is the first step towards creating effective organic semiconductors, which use significantly less water and energy, and produce far less waste than their inorganic counterparts February 16th, 2024

NRL discovers two-dimensional waveguides February 16th, 2024

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

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