Dye-sensitized solar cell technology was invented by Ecole Polytechnique Fédérale de Lausanne (EPFL) professor Michael Grätzel at EPFL in the 1990s and always seemed to have great promise as a cheap alternative to expensive silicon solar cells.
Dye-sensitized cells imitate the way that plants and certain algae convert sunlight into energy. The cells are made up of a porous film of tiny (nanometer-sized) white pigment particles made from titanium dioxide. The latter are covered with a layer of dye which is in contact with an electrolyte solution. When solar radiation hits the dye it injects a negative charge in the pigment nanoparticle and a positive charge into the electrolyte resulting in the conversion of sunlight into electrical energy.
The cells are inexpensive, easy to produce and can withstand long exposure to light and heat compared with traditional silicon-based solar cells but even state-of-the-art dye-sensitized cells only have an overall light conversion efficiency greater than 11%, about half that of silicon cell technology.
Another major drawback to dye-sensitized cell technology is the use of an electrolyte solution which is made up of volatile organic solvents and must be carefully sealed. This, along with the fact that the solvents permeate plastics, has precluded large-scale outdoor application and integration into flexible structures.
But now Grätzel, Shaik Zakeeruddin and colleagues from the Changchun Institute of Applied Chemistry at the Chinese Academy of Sciences have achieved a record light conversion efficiency of 8.2% in solvent-free dye-sensitized solar cells.
While still well behind silicon cells, this breakthrough in efficiency without the use of volatile organic solvents will make it possible to pursue large scale, outdoor practical application of lightweight, inexpensive, flexible dye-sensitized solar films that are stable over long periods of light and heat exposure.
To overcome the limitations expressed above, Grätzel and his colleagues developed a mixture of three solid salts as an alternative to using organic solvents as an electrolyte solution. When the three solid components are mixed together in the right proportion they turn into a melt showing excellent stability and efficiency.
Grätzel is confident that further development of these types of electrolyte mixtures will lead to large-scale practical application of dye-sensitized solar cell technology, reinforcing solar energy's role as a cornerstone of alternative energy production.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Doomsday Dashboard Makes Tracking The Apocalypse Convenient
- Intellectually Gifted Kids And Learning Disabilities Often Go Hand In Hand
- Confirmation Bias: Why The Moon Gets Blamed For A Lot
- High-Intensity Exercise Is Best Before That High Fat Meal
- Urine Is Not Really Sterile
- Another One Bites The Dust - WW Cross Section Gets Back Where It Belongs
- Men Who Eat Produce That Usually Has Higher Pesticide Residues May Have Lower Semen Quality
- "Could we have a new poster child for junk science? Ladies and gentlemen, we have a correlation..."
- "The hull design is nearly the same today as it was back then because aerodynamics haven't changed..."
- "I think if anything Soyuz would be more sensitive. It is a late 60's design with minor updates..."
- "Agreed, mesons are bosons and hadrons...."
- "I applaud Science 2.0 for bringing this study to light for the public. I perform nerve decompression..."
- Counter-intuitive: Generous welfare benefits make people more likely to want to work, not less
- BHPI: New drug stalls estrogen receptor-positive cancer cell growth and shrinks tumors
- The bacterial genetic pathway reason you may stink
- Eating fruits and vegetables with high pesticide residues linked to poor semen quality
- Temperature-sensitive engineering from nature: From tobacco to cyberwood