High endurance organic resistive switching memory based on 1, 2-dicyanobenzene and polymer composites

Abstract

As the emerging data storage technology, organic resistive switching memory (ORSM) possesses numerous superiorities as the substitution for or the complementation of the traditional Si-based semiconductor memory. Poly(3-hexylthiophene) (P3HT) has been widely used as a polymer donor component of ORSMs due to its advantages of high mobility and high chemical stability. Up to now, ORSM based on P3HT has achieved high on/off current ratio (<i>I</i>_on/off), but the endurance still needs to be improved. Herein, high endurance ORSMs based on 1,2-dicyanobenzene (O-DCB) and P3HT composite are fabricated by spin coating and thermally evaporating, and exhibit non-volatile and bipolar memory characteristics. The ORSMs based on P3HT:15 wt.% O-DCB and P3HT:30 wt.% O-DCB exhibit the values of <i>I</i>_on/off exceeding 10⁴ and 10³ respectively, and both of them exert excellent endurance of 400 times, retention time of more than 10⁵ s. The mechanism of the switching is explored by linear fitting of <i>I-V</i> curve and electrochemical impedance spectrum . The results indicate that the filling and vacant process of the charge traps induced by O-DCB and the inherent traps in P3HT bulk lead to a resistive switching effect. The negative or positive bias triggers off trapping and detrapping process, which leads the conductive way of charges to change, resulting in the resistive switching effect. The excellent endurance of ORSM is attributed to the uniform distribution of O-DCB in P3HT bulk because of the small molecular size and high solubility of O-DCB, resulting in well-distributed and stable charge traps. On the other hand, the out-bound planarity of O-DCB molecular promotes the close interaction with the conjugated chains of P3HT. This study enlightens an effective strategy to carry out high-endurance ORSM and facilitates their electronic applications in future.