ZME Science
No Result
View All Result
ZME Science
No Result
View All Result
ZME Science

Home → Science → Nanotechnology

Excition fission model could vastly improve solar cell efficiency

Mara BujorbyMara Bujor
May 7, 2014
in Nanotechnology, News, Renewable Energy
A A
Share on FacebookShare on TwitterSubmit to Reddit
Troy Van Voorhis, professor of chemistry (left), and Marc Baldo, professor of electrical engineering (right). Photo: MIT
Troy Van Voorhis, professor of chemistry (left), and Marc Baldo, professor of electrical engineering (right). Photo: MIT

The most basic principle of a solar cell is that it works by transferring the energy from an incoming photon (light) to a molecule, which causes one or more electrons to become displaced until an electrical current is formed. That’s the absolute gist of it, only besides electricity, some of the incoming photon energy gets lost as waste heat. Oddly enough, however, there are some organic materials that behave in the opposite way: when extra energy is given, more electrons form.

Weird physics

A team of researchers at MIT used both experiments and theoretical models to explain the mechanics of this phenomenon – called singlet exciton fission – and thus help solar cells become vastly more efficient.

The phenomenon was first observed in the 1960s, yet the exact mechanism involved has become the subject of intense controversy in the field. MIT’s Troy Van Voorhis, professor of chemistry, and Marc Baldo, professor of electrical engineering, led a team which investigated this odd behaviour. They synthesized and gathered materials made of four types of exciton fission molecules decorated with various sorts of “spinach” — bulky side groups of atoms that change the molecular spacing without altering the physics or chemistry. They then subjected these to various experiments to determine their fission rate.

The MIT team turned to experts including Moungi Bawendi, the Lester Wolfe Professor of Chemistry, and special equipment at Brookhaven National Laboratory and the Cavendish Laboratory at Cambridge University, under the direction of Richard Friend.

Experimental data and theoretical models confirm once and for all what was first proposed some 50 years ago: when excess energy is available in these materials, an electron in an excited molecule swaps places with an electron in an unexcited molecule nearby. The result: one photon in, two electrons out. “

“The simple theory proposed decades ago turns out to explain the behavior,” Van Voorhis says. “The controversial, or ‘exotic,’ mechanisms proposed more recently aren’t required to explain what’s being observed here.”

As such, the results provide a solid guideline for designing solar cells with these sort of exotic materials. They show that molecular packing is important in defining the rate of fission — but only to a point. When the molecules are very close together, the electrons move so quickly that the molecules giving and receiving them don’t have time to adjust. Indeed, a far more important factor is choosing a material that has the right inherent energy levels.

David Reichman, a professor of chemistry at Columbia University who was not involved in this research, considers the new findings “a very important contribution to the singlet fission literature. Via a synergistic combination of modeling, crystal engineering, and experiment, the authors have provided the first systematic study of parameters influencing fission rates,” he says. Their findings “should strongly influence design criteria of fission materials away from goals involving molecular packing and toward a focus on the electronic energy levels of selected materials.”

RelatedPosts

Concentrated photovoltaic, now on your rooftop
Popeye’s secret: spinach provides key insight that might one day lead to artificial photosynthesis
Solar paint promises to turn any surface into a solar cell
Scientists Detect Light Traversing the Entire Human Head—Opening a Window to the Brain’s Deepest Regions

The results are reported in the journal Nature Chemistry. 

Tags: electronexcitonphotonsolar cell

ShareTweetShare
Mara Bujor

Mara Bujor

Mara is a student preparing to take the plunge and go to college. She's always been interested in anything new and intriguing as long as it made her think. She considers herself far from being a scientist but rather a seeker on his way to new and exciting answers and she's trying to make the internet educate people and show them the interesting part of science.

Related Posts

Inventions

Scientists Detect Light Traversing the Entire Human Head—Opening a Window to the Brain’s Deepest Regions

byTudor Tarita
2 weeks ago
News

Polar rain auroras: scientists explain this spectacular solar event

byMihai Andrei
12 months ago
News

World’s thinnest lens is only three atoms thick. It manipulates light using quantum effects

byTibi Puiu
1 year ago
Green Living

Why transparent solar cells could replace windows in the near future

byRupendra Brahambhatt
3 years ago

Recent news

Coolness Isn’t About Looks or Money. It’s About These Six Things, According to Science

July 1, 2025

Ancient Roman Pompeii had way more erotic art than you’d think

July 1, 2025

Wild Orcas Are Offering Fish to Humans and Scientists Say They May Be Trying to Bond with Us

July 1, 2025
  • About
  • Advertise
  • Editorial Policy
  • Privacy Policy and Terms of Use
  • How we review products
  • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.

No Result
View All Result
  • Science News
  • Environment
  • Health
  • Space
  • Future
  • Features
    • Natural Sciences
    • Physics
      • Matter and Energy
      • Quantum Mechanics
      • Thermodynamics
    • Chemistry
      • Periodic Table
      • Applied Chemistry
      • Materials
      • Physical Chemistry
    • Biology
      • Anatomy
      • Biochemistry
      • Ecology
      • Genetics
      • Microbiology
      • Plants and Fungi
    • Geology and Paleontology
      • Planet Earth
      • Earth Dynamics
      • Rocks and Minerals
      • Volcanoes
      • Dinosaurs
      • Fossils
    • Animals
      • Mammals
      • Birds
      • Fish
      • Amphibians
      • Reptiles
      • Invertebrates
      • Pets
      • Conservation
      • Animal facts
    • Climate and Weather
      • Climate change
      • Weather and atmosphere
    • Health
      • Drugs
      • Diseases and Conditions
      • Human Body
      • Mind and Brain
      • Food and Nutrition
      • Wellness
    • History and Humanities
      • Anthropology
      • Archaeology
      • History
      • Economics
      • People
      • Sociology
    • Space & Astronomy
      • The Solar System
      • Sun
      • The Moon
      • Planets
      • Asteroids, meteors & comets
      • Astronomy
      • Astrophysics
      • Cosmology
      • Exoplanets & Alien Life
      • Spaceflight and Exploration
    • Technology
      • Computer Science & IT
      • Engineering
      • Inventions
      • Sustainability
      • Renewable Energy
      • Green Living
    • Culture
    • Resources
  • Videos
  • Reviews
  • About Us
    • About
    • The Team
    • Advertise
    • Contribute
    • Editorial policy
    • Privacy Policy
    • Contact

© 2007-2025 ZME Science - Not exactly rocket science. All Rights Reserved.