Electrical Property of DNA Field-Effect Transistor: Charge Retention Property

We discovered the charge retention property of the field-effect transistor (FET) in a Si gate/SiO2/DNA channel structure. The DNA FET with the Si source and drain showed hole conduction, and the drain current was controlled by the gate voltage application. In addition, the experimental results that currents similar to the space change limited currents (SCLCs) and hysteresis were observed in the drain current-drain voltage (I-d-V-d) characteristics indicate that the negative charges captured at the trap sites in the DNA enhance the hole currents. Also, the drain currents increased as the repetition number of the measurement increased. However, by inserting the refresh process of gate voltage application of -50 V between each measurement, the current increase was restrained. This phenomenon indicates that the trap and detrap process of electrons occurs in the DNA channel depending on the gate voltage application. The charge retention mechanism was also discussed. (C) 2012 The Japan Society of Applied Physics