Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > New ORNL method could unleash solar power potential

(Top) A phasor plot of the transient absorption data shows the presence of free charges and excitons; a false colored image shows their contributions at different spatial positions.
CREDIT: ORNL
(Top) A phasor plot of the transient absorption data shows the presence of free charges and excitons; a false colored image shows their contributions at different spatial positions.

CREDIT: ORNL

Abstract:
Measurement and data analysis techniques developed at the Department of Energy's Oak Ridge National Laboratory could provide new insight into performance-robbing flaws in crystalline structures, ultimately improving the performance of solar cells.

New ORNL method could unleash solar power potential

Oak Ridge, TN | Posted on March 16th, 2016

While solar cells made from light-harvesting perovskite (an organic-inorganic hybrid) materials have recently eclipsed the 20 percent efficiency mark, researchers believe they could do better if they had a clearer picture of energy flow at the nanometer scale. The ORNL discovery, described in a paper published in ACS Photonics, synchronizes microscopy, ultra-short pulses of laser light and data analytics to extract images with single-pixel precision, providing unprecedented detail.

"If we can see exactly and in real time what is happening, we can map out the electronic processes in space instead of relying on snapshots gleaned from spatial averages," said Benjamin Doughty, one of the authors and a member of ORNL's Chemical Sciences Division.

Armed with information about what electrons are doing inside the material, researchers believe they can make improvements that lead to solar cells that are more efficient and potentially less expensive.

"With conventional approaches of studying photovoltaic materials, we are unable to accurately map out electronic processes and how electrons are getting lost," Doughty said. "Those processes can translate into losses in efficiency."

The experiment consists of optically pumping the thin film sample with a 50 femtosecond -- or 50 millionths of a billionth of a second -- laser pulse and then measuring changes in light absorption with a second laser pulse in the material. The technique, called femtosecond transient absorption microscopy, consists of a tabletop of lasers, optics and a microscope. The net result is a pixel-by-pixel map of the material being studied and information researchers can use to improve performance.

"The ability to identify what will be created after the solar cell absorbs a photon, either a pair of free charges or their bound form called an exciton, is crucial from both fundamental and applied perspectives," said co-author Yingzhong Ma, who led the research team. "We found that both free charges and excitons are present, and the strength of our approach lies in not only identifying where they are but also determining what their relative contributions are when they are both present at a given spatial location."

A key remaining challenge is to understand what causes the observed spatial difference, said Ma, so he and colleagues are exploring an all-optical imaging approach that would allow them to correlate electronic dynamics with underlying structural information. This approach may also help researchers map and understand perovskite degradation issues associated with moisture. Ma noted that this must be resolved before solar cells based on this class of materials can be successful.

Other team members were Mary Jane Simpson, the lead author and a postdoctoral research associate in the Chemical Sciences Division, and Bin Yang and Kai Xiao of ORNL's Center for Nanophase Materials Science.

This research was funded by DOE's Office of Science. Perovskite sample preparation was done at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility.

####

About Oak Ridge National Laboratory
UT-Battelle manages ORNL for the DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov/.

For more information, please click here

Contacts:
Ron Walli

865-576-0226

Copyright © Oak Ridge National Laboratory

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 Links

The paper, titled "Separation of Distinct Photoexcitation Species in Femtosecond Transient Absorption Microscopy," is available at:

Related News Press

News and information

Elliot Scientific now representing Raman Imaging specialists WITec in the UK and Eire - Unique correlative analysis in one instrument: Raman/AFM, Raman/SNOM December 10th, 2018

A new 'spin' on kagome lattices: Team's findings shed new light on the presence of spin-orbit coupling and topological spin textures in kagome lattices December 9th, 2018

Milestone for bERLinPro: Photocathodes with high quantum efficiency December 8th, 2018

Harnessing the power of 'spin orbit' coupling in silicon: Scaling up quantum computation December 7th, 2018

Laboratories

Scientists produce 3D chemical maps of single bacteria: Researchers at NSLS-II used ultrabright x-rays to generate 3-D nanoscale maps of a single bacteria's chemical composition with unparalleled spatial resolution November 16th, 2018

Unlocking the Secrets of Metal-Insulator Transitions: X-ray photon correlation spectroscopy at NSLS-II's CSX beamline used to understand electrical conductivity transitions in magnetite November 8th, 2018

Nanotech Artisans Sculpt with DNA November 5th, 2018

Leti and Taiwanese National Applied Research Laboratories Announce Collaboration for Microelectronics Innovation: Collaboration Will Facilitate Scientific and Technological Exchanges in Microelectronics, Sharing Platforms and Encouraging PhD Student Exchanges October 23rd, 2018

Organic Electronics

Amazingly 'green' synthesis method for high-tech dyes: Dyes that are also of great interest for organic electronics have recently been prepared and crystallised at TU Wien. All that is required is just water, albeit under highly unusual conditions. August 10th, 2018

DNA drives design principles for lighter, thinner optical displays: Lighter gold nanoparticles could replace thicker, heavier layered polymers used in displays’ back-reflectors June 27th, 2018

Switching with molecules: Molecular switch will facilitate the development of pioneering electro-optical devices May 25th, 2018

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Govt.-Legislation/Regulation/Funding/Policy

A new 'spin' on kagome lattices: Team's findings shed new light on the presence of spin-orbit coupling and topological spin textures in kagome lattices December 9th, 2018

It's not a shock: Better bandage promotes powerful healing November 29th, 2018

French Researchers Extend Reach of Mass Spectrometry with Nanomechanical Resonators: Neutral Mass Spectrometry’ Fills Gap In Existing Weighing Technologies November 27th, 2018

Three CEA Projects Awarded European Research Council Synergy Grants November 26th, 2018

Discoveries

A new 'spin' on kagome lattices: Team's findings shed new light on the presence of spin-orbit coupling and topological spin textures in kagome lattices December 9th, 2018

Milestone for bERLinPro: Photocathodes with high quantum efficiency December 8th, 2018

Harnessing the power of 'spin orbit' coupling in silicon: Scaling up quantum computation December 7th, 2018

Iran Develops Water-Repellent Nano-Paint December 5th, 2018

Announcements

Elliot Scientific now representing Raman Imaging specialists WITec in the UK and Eire - Unique correlative analysis in one instrument: Raman/AFM, Raman/SNOM December 10th, 2018

A new 'spin' on kagome lattices: Team's findings shed new light on the presence of spin-orbit coupling and topological spin textures in kagome lattices December 9th, 2018

Milestone for bERLinPro: Photocathodes with high quantum efficiency December 8th, 2018

Harnessing the power of 'spin orbit' coupling in silicon: Scaling up quantum computation December 7th, 2018

Energy

New catalyst produces cheap hydrogen November 30th, 2018

New insight into molecular processes November 23rd, 2018

Rice U. scientists form flat tellurium: Two-dimensional element shows promise for solar cells and other optoelectronics October 26th, 2018

How to mass produce cell-sized robots: Technique from MIT could lead to tiny, self-powered devices for environmental, industrial, or medical monitoring October 24th, 2018

Personal Care/Cosmetics

A Comprehensive Guide: The Future of Nanotechnology September 13th, 2018

Graphene finds new application as anti-static hair dye: New formula works as well as commercial permanent dyes without chemically altering hairs March 22nd, 2018

Programmable materials find strength in molecular repetition May 23rd, 2016

Common nanoparticle has subtle effects on oxidative stress genes May 11th, 2016

Solar/Photovoltaic

Study unlocks full potential of 'supermaterial' graphene: Researchers remove silicon contamination from graphene to double its performance November 30th, 2018

Perovskite solar cells leap toward commercialization September 28th, 2018

September 5th, 2018

NUST MISIS scientists present metamaterial for solar cells and nanooptics July 23rd, 2018

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