In a groundbreaking study published in the journal “Discover Nano” (translated from German as “Explore Nano”), researchers have unveiled new insights into the behavior of organic field-effect transistors (OFETs), a discovery that could significantly impact the energy sector. The research, led by Souren Grigorian from the Department of Physics at the University of Siegen, focuses on the structure-property relationships of a specific semiconductor material, 5,5′′′′-dihexyl-2,2′:5′,2′′:5′′,2′′′:5′′′,2′′′′-quinquethiophene (DH5T), under operating conditions.
Using a custom-made setup designed for in-operando tests of OFETs, Grigorian and his team employed Grazing Incident Wide Angle X-ray Scattering (GIWAXS) to conduct a detailed, spatially resolved microstructural characterization of the active layer. This innovative approach allowed them to correlate the complex microstructure of the DH5T thin film with its electrical behavior under actual operating conditions.
The GIWAXS measurements revealed significant anisotropy in the DH5T thin films when subjected to source-drain applied voltages (Vsd). “The microstructure remained relatively stable in the out-of-plane direction, suggesting that this orientation is less affected by the applied voltages,” explained Grigorian. However, in the in-plane direction, the researchers observed an increase in the π–π stacking of the DH5T molecules, indicating a stronger response to the applied voltage.
One of the most striking findings was the observation of a higher tensile strain, exceeding 1%, at a Vsd of −10 V. This suggests that the application of voltage induces significant structural reorganization in the thin film. “This structural reorganization could have profound implications for optimizing the performance of OFETs in practical applications,” Grigorian noted.
The implications of this research for the energy sector are substantial. OFETs are crucial components in various energy-harvesting and energy-storage devices, including solar cells and batteries. Understanding and controlling the microstructure of these materials can lead to more efficient and reliable devices, ultimately contributing to a more sustainable energy future.
As the world continues to seek innovative solutions to the energy crisis, research like this offers a glimpse into the potential of advanced materials and technologies. By unraveling the intricate relationships between structure and properties at the nanoscale, scientists are paving the way for the next generation of energy technologies. This study, published in “Discover Nano,” marks a significant step forward in this exciting field.