Papers by Author: Shashi Paul

Abstract: Intensive research is currently underway to exploit the highly interesting properties of nano-sized particles and organic molecules for optical, electronic and other applications. Recently, it has been shown that nano-sized particles and small organic molecules embedded in polymer matrices can be used to realise memory devices. Such memory devices are simple to fabricate via the spin-on technique. This work presents an attempt to use sea salt, embedded in polyvinyl acetate, in the making of the memory devices. A polymer blend of polyvinyl acetate and sodium chloride (NaCl) was prepared in methanol and spin coated onto a glass substrate marked with thin Al tracks and a top contact was evaporated onto the blend after drying - this resulted in a metal-organic-metal (MOM) structure. The current-voltage (I-V) behaviour of MOM devices shows that the devices can be switched from a high conductivity state to a low conductivity state, by applying an external electric field - this property can be exploited to store data bits. The possible charging mechanism, based on the electric dipole formation, is presented in this work. Polymer blends of polyvinyl acetate with nano-particles of BaTiO3 are also investigated to further our understanding of charging mechanism(s).

Abstract: Organic and polymer based electronic devices are currently the subject of a great deal of scientific investigation and development. This interest can be attributed to the low cost, easy processing steps and simple device structures of organic electronics when compared to conventional silicon and inorganic electronics. In the field of organic electronic memories, non-volatile, rewritable polymer memory devices (PMDs) have shown promise as a future technology where cost and compatibility with flexible substrates are important factors. In this paper PMDs based on active layers containing an admixture of polystyrene, gold nanoparticles and 8-hydroxyquinoline will be presented, showing the devices’ electrical characteristics and memory performance attributes, and where possible discussing possible mechanisms of operation.