School of Advanced Materials Engineering, Kookmin University, Jeongneung-dong, Seongbuk-gu, Seoul 136-702, Korea.
Nanotechnology. 2010 May 7;21(18):185704. doi: 10.1088/0957-4484/21/18/185704. Epub 2010 Apr 9.
It is demonstrated that notable resistive switching memory properties depending on voltage polarity (i.e. bipolar switching properties) can be obtained from the layer-by-layer (LbL) assembled multilayers based on transition metal oxides and metal nanoparticles. Cationic poly(allylamine hydrochloride) and anionic titania precursor layers were deposited alternately onto Pt-coated Si substrates using an electrostatic LbL assembly process. Anionic Pt nanoparticles (Pt(NP)) with about 5.8 nm diameter size were also inserted within the multilayers using the same interactions mentioned above. These multilayers were converted to Pt(NP)-embedded TiO(2) films by thermal annealing and the films were then coated with a top electrode. When external bias was applied to the devices, bipolar switching properties were observed at low operating voltages showing the high ON/OFF ratio (>10(4)) and the stable device performance. These phenomena were caused by the presence of Pt(NP) inserted within TMO films.
研究表明，通过层层（LbL）组装的过渡金属氧化物和金属纳米粒子多层膜，可以获得依赖于电压极性的显著电阻开关记忆特性（即双极开关特性）。采用静电 LbL 组装工艺，将阳离子聚（盐酸烯丙胺）和阴离子钛前驱体层交替沉积在 Pt 涂覆的 Si 衬底上。通过上述相同的相互作用，将直径约为 5.8nm 的阴离子 Pt 纳米粒子（Pt(NP)）插入多层膜中。通过热退火将这些多层膜转化为 Pt(NP)嵌入的 TiO(2)薄膜，然后在薄膜上涂覆顶电极。当将外部偏压施加到器件上时，在低工作电压下观察到双极开关特性，表现出高的 ON/OFF 比（>10(4)）和稳定的器件性能。这些现象是由插入 TMO 薄膜中的 Pt(NP)引起的。
