- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
A groundbreaking new equation developed in part by researchers at the University of Michigan could do for organic semiconductors what the Shockley ideal diode equation did for inorganic semiconductors: help to enable their wider adoption.
Without the Shockley equation, the computers of today would not be possible.
Developed in 1949 by William Shockley, the inventor of the transistor, the Shockley equation describes the relationship between electric current and voltage in inorganic semiconductors such as silicon.
The new equation describes the relationship of current to voltage at the junctions of organic semiconductorsócarbon-rich compounds that don't necessarily come from a biological source, but resemble them. Organic semiconductors present special challenges for researchers because they are more disordered than their inorganic counterparts. But they could enable advanced solar cells, thin and intense OLED (organic light-emitting diode) displays, and high-efficiency lighting.
"The field of organic semiconductor research is still in its infancy. We're not making complicated circuits with them yet, but in order to do that someday, we need to know the precise relationship of current and voltage. Our new equation gives us fundamental insights into how charge moves in this class of materials. From my perspective, it's a very significant advance," said Steve Forrest, the William Gould Dow Collegiate Professor of Electrical Engineering and U-M vice president for research.
Forrest and his doctoral students, Noel Giebink (now at Argonne National Laboratories) and Brian Lassiter, in the U-M Department of Electrical Engineering and Computer Science, contributed to this research. Two papers on the work are published in the current edition of Physical Review B.
About six years ago, researchers in Forrest's lab realized that they could use Shockley's equation to describe the current/voltage relationship in their organic solar cells to a degree.
"It fit nicely if you didn't look too hard," Forrest said.
Their findings were published, and from that time on, many physicists and engineers used the Shockley equation for organic semiconductors even though it didn't describe the physics perfectly. The new equation does.
Forrest says it will allow researchers to better describe and predict the properties of the different organic semiconductors they're working with. And in that way, they'll be able to more efficiently choose which material best suits the needs of the device they're working on.
"People have been investigating organic semiconductors for 70 or 80 years, but we're just entering the world of applications," Forrest said. "This work will help advance the field forward."
The papers are titled, "The Ideal Diode Equation for Organic Heterojunctions. I. Derivation and Application," and "The Ideal Diode Equation for Organic Heterojunctions. II. The Role of Polaron Pair Recombination."
Forrest is also a professor in the departments of Physics, and Materials Science and Engineering. Others contributing to this work are affiliated with Argonne National Laboratory's Center for Nanoscale Materials and Northwestern University.
This research is funded in party by the Department of Energy's Office of Basic Energy Sciences through the U-M Center for Solar and Thermal Energy Conversion, and the Argonne-Northwestern Solar Energy Research Center.
About University of Michigan College of Engineering
The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At $180 million, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. Michigan Engineering's premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference.
For more information, please click here
Nicole Casal Moore
Phone: (734) 647-7087
Copyright © University of Michigan College of EngineeringIf 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.
|Related News Press|
News and information
Designing ultrasound tools with Lego-like proteins August 29th, 2016
Meteorite impact on a nano scale August 29th, 2016
Graphene under pressure August 26th, 2016
Display technology/LEDs/SS Lighting/OLEDs
New approach to determining how atoms are arranged in materials August 25th, 2016
Thomas Swan and NGI announce unique partnership July 28th, 2016
Lehigh engineer discovers a high-speed nano-avalanche: New findings published in the Journal of Electrochemical Society about the process involving transformations in glass that occur under intense electrical and thermal conditions could lead the way to more energy-efficient glas August 24th, 2016
New flexible material can make any window 'smart' August 23rd, 2016
Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016
Let's roll: Material for polymer solar cells may lend itself to large-area processing: 'Sweet spot' for mass-producing polymer solar cells may be far larger than dictated by the conventional wisdom August 12th, 2016
NREL technique leads to improved perovskite solar cells August 11th, 2016
Tiny high-performance solar cells turn power generation sideways August 5th, 2016