Navigation Links
Discovery of a 'dark state' could mean a brighter future for solar energy
Date:12/17/2011

AUSTIN, Texas The efficiency of conventional solar cells could be significantly increased, according to new research on the mechanisms of solar energy conversion led by chemist Xiaoyang Zhu at The University of Texas at Austin.

Zhu and his team have discovered that it's possible to double the number of electrons harvested from one photon of sunlight using an organic plastic semiconductor material.

"Plastic semiconductor solar cell production has great advantages, one of which is low cost," said Zhu, a professor of chemistry. "Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies."

Zhu and his team published their groundbreaking discovery Dec. 16 in Science.

The maximum theoretical efficiency of the silicon solar cell in use today is approximately 31 percent, because much of the sun's energy hitting the cell is too high to be turned into usable electricity. That energy, in the form of "hot electrons," is instead lost as heat. Capturing hot electrons could potentially increase the efficiency of solar-to-electric power conversion to as high as 66 percent.

Zhu and his team previously demonstrated that those hot electrons could be captured using semiconductor nanocrystals. They published that research in Science in 2010, but Zhu says the actual implementation of a viable technology based on that research is very challenging.

"For one thing," said Zhu, "that 66 percent efficiency can only be achieved when highly focused sunlight is used, not just the raw sunlight that typically hits a solar panel. This creates problems when considering engineering a new material or device."

To circumvent that problem, Zhu and his team have found an alternative. They discovered that a photon produces a dark quantum "shadow state" from which two electrons can then be efficiently captured to generate more energy in the semiconductor pentacene.

Zhu said that exploiting that mechanism could increase solar cell efficiency to 44 percent without the need for focusing a solar beam, which would encourage more widespread use of solar technology.

The research team was spearheaded by Wai-lun Chan, a postdoctoral fellow in Zhu's group, with the help of postdoctoral fellows Manuel Ligges, Askat Jailaubekov, Loren Kaake and Luis Miaja-Avila. The research was supported by the National Science Foundation and the Department of Energy.

Science Behind the Discovery

  • Absorption of a photon in a pentacene semiconductor creates an excited electron-hole pair called an exciton.
  • The exciton is coupled quantum mechanically to a dark "shadow state" called a multiexciton.
  • This dark shadow state can be the most efficient source of two electrons via transfer to an electron acceptor material, such as fullerene, which was used in the study.
  • Exploiting the dark shadow state to produce double the electrons could increase solar cell efficiency to 44 percent.


'/>"/>

Contact: Xiaoyang Zhu
zhu@cm.utexas.edu
512-471-9914
University of Texas at Austin
Source:Eurekalert

Related biology technology :

1. Affitech and Omeros Enter Into Antibody Discovery and Development Agreement
2. Concentric Named Professional Agency of Record for Discovery Labs SURFAXIN(R)
3. ChanTest to Highlight the Worlds Largest Catalog of Ion Channel-Expressing Cell Lines and Discovery Services at Ion Channel Targets, Booth 5
4. Biotechnology & Drug Discovery Markets Push Up Demand for Lab Automation Products, According to a New Report by Global Industry Analysts
5. Assay Designs(TM), Inc. and the Spinal Muscular Atrophy Foundation Announce Collaboration To Accelerate the Discovery of New Therapeutics for Spinal Muscular Atrophy (SMA)
6. ChanTest to Highlight the Worlds Largest Catalog of Ion Channel-Expressing Cell Lines and Discovery Services at Assays & Cellular Targets Conference, Booth 11
7. Affitech Announces Second Milestone in Roche Antibody Discovery Collaboration
8. The Lilly TB Drug Discovery Initiative Begins Work on New Compounds to Fill Early-Stage TB Drug Pipeline
9. Update: The Lilly TB Drug Discovery Initiative Begins Work on New Compounds to Fill Early-Stage TB Drug Pipeline
10. deCODE Discovery Sheds Light on Risk of the Most Common Form of Skin Cancer
11. Global Drug Discovery Technologies Market to Exceed $57 Billion by 2012, According to a New Report by Global Industry Analysts
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/23/2017)... ... 2017 , ... Ellen Matloff, president and CEO of My ... a 2017 Women of Innovation® finalist. Matloff will be among several women to ... dinner recognizes women accomplished in science, technology, engineering and math (STEM), along with ...
(Date:3/23/2017)... 23, 2017  Agriculture technology company Cool Planet has ... note conversion to commercialize its Cool Terra and Cool ... developing products that are simultaneously profitable as well as ... last 18 months. This latest round of funding was ... The company,s primary product, Cool Terra, ...
(Date:3/22/2017)... ... March 22, 2017 , ... Researchers face a ... lab samples to full-size tissues, bones, even whole organs to implant in people ... delivers blood deep into the developing tissue. , Current bioengineering techniques, including ...
(Date:3/22/2017)... Oramed Pharmaceuticals Inc. (NASDAQ: ... ), a clinical-stage pharmaceutical company focused on ... today that Dr. Miriam Kidron , Oramed,s ... "Oral Insulin for Diabetes Treatment: Bypassing the Roadblock," ... Peptide Therapeutics (OPT) Boston Conference in Cambridge, ...
Breaking Biology Technology:
(Date:3/7/2017)... Brandwatch , the leading social intelligence company, today ... to uncover insights to support its reporting, help direct future ... UK,s leading youth charity will be using Brandwatch Analytics social listening ... better understanding of the topics and issues that are a priority ... ...
(Date:3/2/2017)... , March 2, 2017 Summary This ... Perrigo and its partnering interests and activities since 2010. ... Read the ... and Alliance since 2010 report provides an in-depth insight into ... sciences companies. On demand company reports are prepared ...
(Date:3/2/2017)... MELBOURNE, Australia , March 2, 2017 ... Therapeutics Ltd (ASX: CYP), has signed an agreement ... researchers from the Monash Biomedicine Discovery Institute and Department ... , to conduct a further preclinical study to support ... the treatment of asthma.  Asthma is ...
Breaking Biology News(10 mins):