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)... Research and Markets has announced the ... to their offering. ... The Global Market for Bioproducts Should Reach ... a CAGR of 8.9%, This research report ... seven major product segments: bio-derived chemicals, biofuels, pharmaceuticals (biodrugs and ...
(Date:3/23/2017)... Colo. , March 23, 2017  GlobeImmune, Inc. ... agreement for the sale of 12,835,490 shares of its ... NantWorks  ecosystem of companies. In connection with the sale of ... $100,000 in cash and issue to GlobeImmune 200,000 shares, ... stock. "We are pleased to enter ...
(Date:3/23/2017)... SEATTLE , March 23, 2017 ... translational development of novel therapies in immuno-oncology, today ... to lead" small molecule compounds that activate interferon ... (RLR) pathways and demonstrate immune-mediated tumor regression in ... in the study who demonstrated complete tumor regression ...
(Date:3/23/2017)... Colo. , March 23, 2017  Agriculture technology ... Series A financing and note conversion to commercialize its ... Planet is focused on developing products that are simultaneously ... $30 million in the last 18 months. This latest ... North Bridge Venture Partners. The company,s ...
Breaking Biology Technology:
(Date:3/22/2017)... Vigilant Solutions , a vehicle location ... announced today the appointment of retired FBI special agent ... business development. Mr. Sheridan brings more than ... focus on the aviation transportation sector, to his new ... Sheridan served as the Aviation Liaison Agent Coordinator (ALAC) ...
(Date:3/13/2017)... Future of security: Biometric Face Matching software  ... ... DERMALOGs Face Matching enables to match face pictures against each other or against ... (PRNewsFoto/Dermalog Identification Systems) ... Matching" is the fastest software for biometric Face Matching on the market. The ...
(Date:3/7/2017)... March 7, 2017   HireVue , the leading ... companies identify the best talent, faster, today announced the ... Officer (CSO) and Diana Kucer as Chief ... seasoned executive team poised to drive continued growth in ... a year of record bookings in 2017. ...
Breaking Biology News(10 mins):