A team of University researchers discovered a mechanism by which organic crystals change their structures and develop certain electronic properties.

The team created organic crystals that change their electronic properties when they are exposed to heat, light, electrical signals or mechanical impulse.

“Organic systems are interesting because when they are packing to form crystals, small changes in the packing could lead to observable changes,” Hyunjoong Chung, graduate student in Engineering, said. “What we were interested in was that the change in shape led to electronic properties of the material.”

Chung and Ying Diao, Engineering professor, worked on the discovery with help from Fengjiao Zhang, a post-doctoral researcher in organic chemistry.

The similar properties of materials, which change their shape, are already used in medical devices, Diao said, and can be observed in nature.

“There’s a virus that can actually go through a similar phase change to deliver DNA,” Diao said. “If we combine these functionalities with electronics, we could start creating materials that can do things that were not possible before.”

Zhang helped set up the first few experiments for the team to help them better understand organic electronics, acquire some data and analyze that data.

“The most interesting part of the paper to me is to investigate the phase transitions induced carrier transport properties, which is important in organic electronics,” Zhang said.

The discovery can be used to investigate and create low power electronics. The property the team discovered could be used to build devices more power-efficient and faster than transistors today, which are the basis for all electronics.

“Right now, electronics are built around transistors, which requires on-and-off switching,” Diao said. “Surprisingly electronics consume almost 10 percent of the world’s electricity, so people have been thinking about lowering the energy cost of these electronics.”

Diao said if we can switch electronic properties using the new mechanism, the molecules all move together with very low energy and very quickly.

Chung said his goal moving forward is to figure out why certain types of molecules behave this way and find more molecules with similar properties.

“We are going deeper into the phase transitions that these molecules cause,” he said.

The findings were published in “Nature Communications” on Jan. 18.

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