DNA-based small molecules of guanine, cytosine, thymine and adenine are adopted for the charge injection layer between the Au electrodes and organic semiconductor, heptazole (C26H16N2). The heptazole-channel organic field effect transistors (OFETs) with a DNA-based small molecule charge injection layer showed higher hole mobility (maximum 0.12 cm2 V-1 s-1) than that of a pristine device (0.09 cm2 V-1 s-1). We characterized the contact resistance of each device by a transfer length method (TLM) and found that the guanine layer among all DNA-based materials performs best as a hole injection layer leading to the lowest contact resistance. Since the guanine layer is also known to be a proper channel passivation layer coupled with a thin conformal Al2O3 layer protecting the channel from bias stress and ambient molecules, we could realize ultra-stable OFETs utilizing guanine/Au contact and guanine/Al2O3 bilayer on the organic channel.
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Acoustics and Ultrasonics
- Surfaces, Coatings and Films