Adjustment of conformation change and charge trapping in ion-doped polymers to achieve ternary memory performance

Abstract

Ion-doped poly(4-vinylpyridine) derivatives (P4VPCz), where in the pendant chains the electronwithdrawing pyridine moiety and acceptor carbazole moiety are linked by a flexible alkyl spacer were designed and synthesized. Sandwiched ITO/P4VPCz/Al devices, made through simple spin-coating processes have shown that they could be tuned from a binary to ternary memory performance, by increasing the carbazole content. P4VPCz2 with a 20% mole ratio of the carbazole moiety shows a binary performance according to the charge trapping of the pyridine acceptor in the polymer, while P4VPCz5 which contains a 50% mole ratio of carbazole in the pendant chains, exhibits a ternary data storage ability, probably induced by double mechanisms (i.e. a conformational change and charge trapping). Interestingly, as the carbazole mole ratio reached 80%, the polymer P4VPCz8 has a high conductivity state, with no switching behavior, because of the large amount of doped ions improving the charge transfer mobility. Thus, we hope can offer a guideline to achieve a high-performance multilevel memory material, via combining different mechanisms as well as doping ions.

The synthesis and flash memory behavior of alternate copolymer containing carbazole donor and perylenediimide derivatives acceptor by the hybridization of organo-silicon

“…[30][31][32] For example, from the regiorandom to regioregular alignments of side carbazoles in PVK derivatives corresponds to the transition from low to high conductivity states. 35 The memory devices are therefore transformed from the OFF to the ON state. Similarly, the low regioregularity of PCzMSi-alt-PDISi and PCzPhSi-alt-PDISi film at the ground state promoted by the flexible Si-O-Si chains does not favor the charge-transfer (CT) interaction of donor and acceptor pendants.…”

The Effect of Random and Block Copolymerization with Pendent Carbozole Donors and Naphthalimide Acceptors on Multilevel Memory Performance

“…Both polymers could be spin‐cast into uniform thin films from solutions in cyclohexanone (12 mg mL −1 ). The relative molecular weight (M n ) of random copolymer PMCz 8 ‐ co ‐PMBNa 2 was 20 205 g mol −1 , with a polydispersity index (PDI) of 1.52, and the ratio of MCz/MBNa segments was measured by using the UV/Vis absorption of a solution of MBNa in DMF (see ref ). Subsequently, the M n of polymer R‐PMCz [R=Reversible Addition‐Fragmentation Chain Transfer Polymerization (RAFT)] was 9 447, with a PDI of 1.26, whilst that of the final block polymer, PMCz 8 ‐ b ‐PMBNa 2 , was 12 551 g mol −1 , with a PDI of 1.33.…”

“…In our previous work, we designed a ternary OMD that was based on polymer P4VPCz (poly(4‐vinylpyridine) derivatives), which contained pyridine and carbazole (Cz) groups in the side chain. The conduction mechanism for the device based on this polymer was found to involve a combination of conformational‐change and charge‐trapping mechanisms . Furthermore, two pendent copolymers, poly(2‐(naphthalen‐1‐yloxy)ethyl 5‐(2‐(7‐bromo‐1,3‐dioxo‐4,5‐dihydro‐1H‐benzo[de]isoquinolin‐2(3H)‐yl)ethoxy)‐2,2,4‐trimethylhex‐5‐enoate) (PMNB) and (poly(2‐(naphthalen‐1‐yloxy)ethyl 5‐(2‐((2‐butyl‐1,3‐dioxo‐2,3‐dihydro‐1H‐benzo[de]isoquinolin‐6‐yl)amino)ethoxy)‐2,2,4‐trimethylhex‐5‐enoate) (PMNN), which contained electron‐donor (naphthalene) and electron‐acceptor (1,8‐naphthalimide; Na) units in their side chains, were also synthesized.…”

Nonvolatile resistive memory devices based on ferrocene‐terminated hyperbranched polyimide derived from different dianhydrides

“…The results exhibit flat and smooth surface of the polymer films with low roughness of 0.74, 1.29, 0.80, and 0.76 nm for BTDA‐HBPI‐Fc, BPDA‐HBPI‐Fc, ODPA‐HBPI‐Fc, and BDDE‐HBPI‐Fc, respectively. This faultless surface morphology can not only facilitate the hole injection process, but also prevent the permeation of Al into the film during the vacuum deposition of Al electrode …”