Control of photocurrent and multi-state memory by polar order engineering in 2H-stackedα-In_(2)Se_(3) ferroelectric

2Hα-In_(2)Se_(3)铁电体中极序工程控制的光电流和多态存储器

Controlling the polar order in ferroelectric materials may enrich the diversity of their property and functionality,offering new opportunities for the design of novel electronic and optoelectronic devices.In this paper,we report a planar multi-state memory device built upon a twodimensional(2D)van der Waals layered ferroelectric material,2Hα-In_(2)Se_(3).Three(high,median and low)resistance states are demonstrated to be interconvertible in this device with a fast switching speed,excellent endurance and retention performances via the modulation of the polar order of the ferroelectricα-In_(2)Se_(3) layers under an in-plane electric field.Remarkably,reversible switching between the median-resistance state and the low-resistance state can be achieved by an ultralow electric field of 1-2 orders of magnitude smaller than the reported values in other 2D ferroelectric materialbased memory devices.Furthermore,the three different polar order states are discovered to exhibit distinctive photoresponses.These results demonstrate great potentials ofα-In_(2)Se_(3)in nonvolatile high-density memory and advanced optoelectronic device applications.

控制铁电材料的极序可以丰富其特性和功能的多样性,为设计新型电子和光电子器件提供新的机会.本文报道了一种基于二维(2D)范德瓦尔斯(vdW)层状铁电材料2Hα-In_(2)Se_(3)的面内多态存储器件.通过施加面内电场调控铁电α-In_(2)Se_(3)层的极序,实现了可以相互切换的三种电阻态,其具有快的切换速度、良好的耐久性和保持性.值得注意的是,中间阻态(MRS)和低阻态(LRS)之间可以通过比其他基于2D铁电材料的存储器小1–2个数量级的超低电场来实现可逆切换.此外,还发现这三种不同的极序态表现出了特有的光响应.以上结果表明,α-In_(2)Se_(3)在非易失性高密度存储器和新型光电器件中具有很大的应用潜力.