{"id":629957,"date":"2024-08-06T15:14:05","date_gmt":"2024-08-06T12:14:05","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/stacking-molecules-like-plates-improves-organic-solar-device-performance\/"},"modified":"2024-08-06T15:14:05","modified_gmt":"2024-08-06T12:14:05","slug":"stacking-molecules-like-plates-improves-organic-solar-device-performance","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/stacking-molecules-like-plates-improves-organic-solar-device-performance\/","title":{"rendered":"#Stacking molecules like plates improves organic solar device performance"},"content":{"rendered":"
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\n \"Stacking
\n Molecular structures of the organic semiconductors (top), the performance of the single-component organic solar cell using the stackable molecule (left), and the performance of both heterogeneous organic photocatalysts (right). Credit: Osaka University
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Harnessing the power of the sun is vital for a clean, green future. To do so, we need optoelectronic devices, like solar cells, that can convert light into electricity efficiently. Now, a team led by Osaka University has discovered how to further improve device efficiency: by controlling how light-absorbing molecules stack together.<\/p>\n

Organic optoelectronic devices, such as organic solar cells, are becoming increasingly sought after for their inherent advantages, e.g., flexibility or light weight. Their performance depends on how well their light-absorbing organic molecules convert light energy into free-charge carriers, which carry electric current. The energy needed to generate the free-charge carriers is referred to as exciton-binding energy.<\/p>\n

The lower the exciton-binding energy, the easier it is to generate free-charge carriers, and thus the better the device performance. However, we still struggle to design molecules with low exciton-binding energy in a solid state.<\/p>\n

Upon deeper inspection, the research team found that the exciton-binding energy of solid materials is affected by how their molecules stack together, which is referred to as aggregation.<\/p>\n

“We synthesized two types of similar star-shaped molecules, one with a flexible center and the other with a rigid center,” explains lead author Hiroki Mori. “The individual molecules behaved similarly when they were dispersed in a solution, but quite differently when they were stacked together in thin solid films.”<\/p>\n

The difference in behavior is due to the rigid molecules stacking together well, like plates, whereas the flexible molecules do not. In other words, when in a solid state, the rigid molecule has a much lower exciton-binding energy than the flexible molecule.<\/p>\n

To verify this, the team built a single-component organic solar cell and a photocatalyst using each molecule. The solar cell and photocatalyst made of the rigid molecule showed impressive performance because their low exciton-binding energy led to a high generation of free-charge carriers.<\/p>\n

“Our findings, that making molecules that aggregate well can decrease the exciton-binding energy, are really exciting,” says senior author Yutaka Ie. “This could provide us with a new way to design more efficient optoelectronic devices.”<\/p>\n

The team’s findings<\/a>, published in Angewandte Chemie International Edition<\/i>, show that the interaction between molecules in a solid is important for device performance, and that the design of molecules for high-performance optoelectronic devices should look beyond individual molecular properties.<\/p>\n

This new way of decreasing exciton-binding energy could underpin the driving mechanisms and architecture of the next generation of optoelectronic devices.<\/p>\n

\n More information:<\/strong>
\n Hiroki Mori et al, A Dibenzo[g,p]chrysene\u2010Based Organic Semiconductor with Small Exciton Binding Energy via Molecular Aggregation, Angewandte Chemie International Edition<\/i> (2024). DOI: 10.1002\/anie.202409964<\/a><\/p><\/div>\n
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Provided by
\n Osaka University
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Citation<\/strong>:
\n Stacking molecules like plates improves organic solar device performance (2024, August 6)
\n retrieved 6 August 2024
\n from https:\/\/phys.org\/news<\/a>\/2024-08-stacking-molecules-plates-solar-device.html<\/p>\n

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