• Tech Tech

Researchers design novel light-harvesting method to increase solar cell efficiency by over 35%: 'It can absorb [a lot] of light energy in a relatively thin layer'

At the very least, it's "progress on the road to more efficient utilization of solar energy."

At the very least, it's "progress on the road to more efficient utilization of solar energy."

Photo Credit: iStock

Scientists in Germany are looking to nature for inspiration on how to absorb light to create energy. The result could be a pace-setting efficiency rate for an industry already flush with innovations. 

Plants use photosynthesis to turn sunlight, water, and air pollution into oxygen and sugar. They are good at absorbing a lot of light energy using a relatively small mass, according to experts from the Julius-Maximilians-Universität (JMU) Würzburg in Bavaria. 

A hurdle with solar energy tech to date, according to the JMU experts, is that bulky silicon panels are required to capture enough light to create energy. Thinner, light-sensitive organic dyes weigh less but are not very efficient on their own.

The JMU breakthrough tech can absorb energy from the "entire" visible range using the light-gathering qualities of organic dyes. The method stacked and folded four dye molecules capable of absorbing four crucial wavelengths: ultraviolet, red, purple, and blue, per the lab report. 

"As a result, it can absorb a great deal of light energy in a relatively thin layer, similar to natural light-harvesting systems," JMU chemistry professor Frank Würthner said in the lab summary. 

The team achieved an impressive 38% conversion "of the irradiated light energy over a broad spectral range into fluorescence," the report reads. Fluorescence typically happens when chemicals show visible light after absorbing radiation that is not normally visible, such as ultraviolet light, per a McGill University description.  

Conversely, when the four dyes the JMU researchers were working with were not stacked, only 1% to less than 3% of light was converted to fluorescence. 

"The right combination and skilful spatial arrangement of dye molecules in the stack therefore make a big difference," the researchers note

The project leveraged JMU expertise in organic chemistry, nanosystems chemistry, and physical and theoretical chemistry.

A rendering of the researchers' progress might be the best representation. It shows the chemical structure of the four dyes on the left and then depicts them on the right stacked on top of each other, creating the crucial structure to capture the four light wavelengths.

Experts around the world are working on ways to better capture light energy — and convert it into usable electricity. For example, WAVJA has developed small spheres that can harvest natural and artificial light. The company envisions the unique contraptions one day powering vehicles. 

Better tech and government incentives are making solar setups more accessible to homeowners. Installing a home-based solar system could also save you $1,500 a year on electricity. SaveOnEnergy is an online site that offers free expertise to find a product, installer, and other key information about solar panel systems. 

Switching to renewable electricity can help limit the amount of heat-trapping pollution being churned out by burning fossil fuels. Scientists are learning more about how air pollution, including aerosols and other types, are linked to extreme floods, droughts, and wildfires, per Climate.gov. Research is more clear about how breathing in dirty air, especially for longer periods of time, is linked to severe health problems, including cancer. 

JMU's nature-inspired dye stacking might be another breakthrough to expand renewable solar to more places and limiting the fumes. 

At the very least, it's "progress on the road to more efficient utilization of solar energy," per the summary

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