Caffeine gives solar cells a boost of energy, say scientists, Energy News, and EnergyWorld

Washington DC: A team of scientists discovered that caffeine could be a promising alternative for making traditional solar cells more efficient in converting light into electricity.

According to scientists, it all started with a joke around morning coffee. "One day while we were discussing perovskite solar cells, our colleague said," If we need coffee to increase our energy, then what about perovskites? Would they need coffee to work better? ", Recalled Jingjing Xue.

The spontaneous comment led the team to recall that caffeine in coffee is an alkaloid compound containing molecular structures likely to interact with the precursors of perovskite-based materials, composed of a crystalline structure that form the light-collecting layer in a class of solar cells.

Previous attempts to improve the thermal stability of these solar cells have included improving the perovskite layer by introducing compounds such as dimethylsulfoxide, but researchers have struggled to increase long-term efficiency and stability cells. Nobody had tried caffeine.

Realizing that they might be on something, the team set aside their coffee and began investigating further. They added caffeine to the perovskite layer of forty solar cells and used infrared spectroscopy (which uses infrared radiation to identify chemical compounds) to determine whether caffeine had successfully bonded to the material.

By performing other infrared spectroscopy tests, they observed that carbonyl groups (an oxygen-linked double carbon atom) in caffeine interacted with the lead ions in the layer to create a "molecular latch."

This interaction increased the minimum amount of energy required for the perovskite film to react, increasing the efficiency of the solar cell from 17% to over 20%. Molecular blockage continued to occur when the material was heated, which could help prevent heat from degrading the layer.

"We were surprised by the results.On our first trial of caffeine incorporation, our perovskite solar cells have already achieved the highest efficiency we have achieved in the document," said Rui. Wang, one of the leading researchers of the study published in the Journal de Joule. .

However, while caffeine seems to significantly improve the performance of cells using perovskite to absorb sunlight, researchers do not think it will be useful for other types of solar cells.

The unique molecular structure of caffeine only allows it to interact with the precursors of perovskite, which could give this variety of solar cells an edge in the market. Perovskite solar cells already have the advantage of being cheaper and more flexible than their silicon counterparts.

They are also easier to manufacture – perovskite cells can be made from solution-based precursors as opposed to solid crystal ingots. After further research, Wang believes that caffeine could facilitate large-scale production of perovskite solar cells.