a College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, 199 Ren'ai Road, Suzhou 215123, China
Polym. Chem. 2014, 5, 2602-2610
An organic small molecule 4-(1,3-diphenyl-4,5-dihydro-1H-pyrazol-5-yl)-N,N-dimethylaniline (ATPP) bearing a pyrazoline moiety was investigated as an electrical memory material. ATPP as an electro-active film was fabricated by thermal evaporation and then prepared as a sandwich memory device (ITO/ATPP/Al). The as-prepared device exhibited different memory behaviors from nonvolatile ‘switch-off’ to volatile static random access memory (SRAM) via decreasing the compliance currents from 0.1 A to 0.001 A. To avoid the switch-off phenomenon caused by the diffusion of aluminium (Al) atoms, a hyperbranched polystyrene (HPPS) through the copolymerization of ‘inimer’ based on ATPP and styrene using self-condensing vinyl polymerization (SCVP) was introduced herein. The hyperbranched structure of HPPS widened the distance between the inimers and reduced the possibility of Al atoms penetration. The HPPS-based memory device exhibited stable SRAM behavior, even at a compliance of 0.1 A with a low switching threshold voltage of about −2.5 V and an ON/OFF current ratio in excess of 104. The SRAM performance of ATPP and HPPS was attributed to the unstable electric-field-induced intramolecular charge transfer (ICT), which was verified by theoretical calculation and UV-vis spectra changes before and after applying the electric field.
链接：
http://pubs.rsc.org/en/content/articlelanding/2014/py/c3py01588b#!divAbstract
