Qing Bao,Hua Li,Yang Li,Jinghui He,Qingfeng Xu,Najun Li,Dongyun Chen,Lihua Wang,Jianmei Lu
In this paper, two acceptor-donor-acceptor (A-D-A) type organic small molecules, 4,4'-(5,5'-(benzo[c] [1,2,5]thiadiazole-4,7-diyl)bis(3-hexylthiophene-5,2-diyl))bis(N-(4-nitrophenyl)-N-phenylaniline) (NTPA 2 TBT) and 4,4'-(5,6-difluorobenzo[c] [1,2,5]thiadiazole-4,7-diyl)bis(N-(4-nitrophenyl)-N-phenylaniline) (NTPA 2 BTF 2 ), were synthesized and fabricated into resistive random access memory devices. Compared with our previously reported molecule NTPA 2 BT, NTPA 2 TBT has 3-hexylthiophene linkages bridging its donor and acceptor, while there are two additional fluorine atoms in the benzothiadiazole moiety for NTPA 2 BTF 2. Both the fabricated memory devices based on these two new molecules perform nonvolatile ternary memory characteristics with lower threshold voltages , higher reproducibility and better stability. The addition of 3-hexylthiophene bridges significantly promotes the planarity of the conjugation backbone and facilitates the molecular stacking, while the substitution hydrogen by fluorine improves the intermolecular interaction , and thus also induces an ordered molecular stacking. The insertion of 3-hexylthiophene bridges or fluorine atoms could be an effective strategy of tailoring organic molecules to improve data storage performance with lower power consumption.
Yadan Deng,Jingzan Jiang,Jun Sun,Yufeng Hu,Qiuhong Cui,Zhenbo Deng,Zhidong Lou,Yanbing Hou,Feng Teng
Fabrication of nanowires in polymer films can dramatically enhance the mobility of thin-film transistors (TFTs). Unlike the popular method of forming nanowires after spin-coating films, here a water-bath method to fabricate the micrometer-long nanowires in the poly(3-hexylthiophene) (P3HT) solution is introduced, which is suitable for large-area printing electronic application. The resulting transistor exhibits significantly enhanced mobility and excellent device stability. However, the threshold voltage of the device is increased, compared with the amorphous film device. The underlying mechanism of the mesoscale crystalline induced threshold voltage increase has been rarely studied. The temperature-dependent characteristics imply that the activation energy of the device with nanowires is higher than that of the amorphous one, indicating nanowires can introduce deep traps. This suggests that the charge transport is mainly limited by the deep traps at the junctions between the nanowires considering the trap density inside the nanowires is significantly low. The deep traps introduced by the junctions can increase the threshold voltage as the device needs higher voltage to fill these traps in the channel before the device is turned on. This explains why the devices with nanowires have an increased threshold voltage while their mobilities are dramatically enhanced.
危险品化学品经营许可证（带存储）