Narrowing Down Choices Speeds Up Flexible Organic Semiconductor Development

Though inorganic materials like silicone are strong and fast, researchers have been trying to find organic materials for semiconductors with the flexibility needed to make products like roll up displays a reality. But the time it takes to develop and synthesize enough candidate material for a semiconductor takes years, so researchers at Stanford University (Stanford, CA) and Harvard University (Cambridge, MA) figured out a way to narrow down potential materials so they could focus on the most promising candidate compound.

Starting with a material known as DNTT, which previous research had shown to be a promising organic semiconductor, the team combined this parent material with seven compounds aiming to enhance chemical and electrical properties. To determine how successful the compounds would be as a semiconductor, they need to transfer energy charges quickly and easily from one molecule to another. The team looked at the structural and chemical properties and determined that two compounds would most readily accept a charge, and one was considerably faster in passing the charge between molecules, so it was determined to be the winner.

After a year and a half of perfecting the compound and making enough of it to test, the final yield only produced 3 percent usable material that still had to be purified. But the educated narrowing process picked the right material, which in tests was shown to double the speed of the parent material. In comparison to amorphous silicone used in LCD monitors and televisions, this new material is more than 30 times faster.

The team is hoping to use this predictive approach to not only discover other organic semiconductor materials, also but to apply the method to develop high-efficiency material for organic solar cells, a product in such demand that waiting years to synthesize multiple candidates isn't an option. The work was published in the August 16 issue of Nature Communications.