Researchers at Cornell University have found that colors can help measure how energy moves through a specific type of crystal, called a metal-organic framework (MOF), in which light-sensitive molecules are arranged.

The researchers are looking to develop material that can increase the efficiency of silicon solar cells or any solar cells.

The findings were published in the Journal of the American Chemical Society. 

To develop more efficient next-generation materials for solar energy harvesting, researchers need to learn to control how molecules interact and their coherence when they absorb light.

To gain this control, researchers need methods of evaluation.

The team built different MOFs with two distinct structures based on the level of defects in each. The two MOFs were evaluated under UV light.

One glowed green, showing higher order and less emitted energy. One glowed blue, showing less order and more emitted energy.

The researchers discovered solar panels would harness light on the blue side of the solar spectrum much more efficiently, resulting in a markedly higher power output.

The researchers said if the team can successfully make their discovery work, it would be transformative for solar energy generation.

The result yielded a method for researchers to evaluate more complex materials for solar energy harvesting.

The researchers applied spectroscopic tools they developed to analyze the two MOFs and found when there are more defects, more disorder follows, and higher disorder in material changes its ability to manage energy.

The team discovered that by simply tweaking the processing conditions when making MOFs, they could pack molecules into two different structural forms by controlling the material’s defects.

The MOF that glowed green is more ordered, with most of the molecules behaving in the same way and lower energy emitted.

The blue photons of the other MOF indicate higher energy states, more disorder, and more energy being emitted.

In the context of solar energy, these MOFs are not helpful yet. However, the researchers are already using what they have learned about tuning molecule interactions and measuring energy migration to analyze more complex materials.

Recently, researchers at the Georgia Institute of Technology said they discovered that halide perovskite solar cells are far less stable than previously thought and revealed the thermal instability within the cells’ interface layers.

Last month, researchers at the Helmholtz-Zentrum Berlin produced perovskite solar cells to achieve efficiencies of well above 24%, which are resistant to drop under rapid temperature fluctuations between -60 and +80 degrees Celsius over one hundred cycles.