The bio-organic thin film transistor (BiOTFT) with the DNA and DNA-surfactant complex as a dielectric layer shows memory function. In order to investigate the effect of surfactant structure on the OTFT memory device performance, different kinds of surfactant were introduced. Cetyltrimethylammonium chloride (CTMA), Lauroylcholine chloride (Lau) or Octadecyltrimethylammonium chloride (OTMA) as the cationic surfactant was mixed with DNA to prepare the DNA complex through the electrostatic interaction. In addition, the different molecular weight DNA also has been studied to analyze the effect of DNA chain length on the performance of the physical property. Many kinds of methods including UV-vis, Circular dichiroism (CD) and I-V characteristic have been applied to analyze the property of DNA complex. In conclusion, all of DNA complex with CTMA, OTMA and Lau were revealed to work as the bio-organic thin film transistor memory, and the device fabricated by Lau has the highest ON current and showed better device performance.

A nonvolatile memory based on an organic thin-film transistor (OTFT) with biopolymer of DNA-OTMA as the gate dielectric is fabricated. The device prepared by DNA-OTMA show a very large and metastable hysteresis in the transfer characteristics. In order to obtain the organic thin film transistor memory device with high electronic performance, one of the most widely used method such as post annealing have been applied to improve the quality of gate dielectric layer. In conclusion, the post-annealing at elevated temperatures plays a very important role in the performance of the OTFT memory device.