Resistive switching phenomena for resistive random access memory applications

• Main Author: Sim, Raymond Keng Lim.
• Other Authors: Lee Pooi See
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Materials::Organic/Polymer electronics
• Online Access: http://hdl.handle.net/10356/51138
• Institution: Nanyang Technological University

The organic based resistive switching device, one of the candidates vying to be the next generation’s source of non-volatile memory (NVM) storage has generated substantial interest in recent years due to its potential to providing low cost, flexible and lightweight data storage applications, easily fabricated in less stringent environments. There has been much scrutiny in the study of the resistive switching phenomenon exhibited by this family of devices due to the uncertainty of the switching mechanism by which it operates. Here 2 systems exhibiting resistive switching behavior are investigated, presenting insight in their operating mechanisms. The first system investigates the proton doping effect exhibited by the conjugated polymer polyaniline (PANI), and how modulations in its electrical conductivity can be achieved; either through suppression or disruption of its conductivity network. In the formal, solid state rearrangement of charged counter-ions were used to suppress one of the resonance structures of doped PANI, resulting in an inability of charge translation across the conducting main chain, diminishing electrical conductivity. In the latter, destruction and restoration of the conductivity network was achieved through protonation/ de-protonation of PANI, induced by ferroelectric polarization of poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)). The second system examines the oxidative doping phenomenon of another conjugated polymer, poly(3-hexylthiophene) (P3HT), with changes in its electrical conductivity induced via additional of acceptors. In this section, resistive switching device operating behavior, in particular device switch-on voltage was found to be dependent on energy level differences between P3HT and the acceptors.