新型低维铁电材料及其器件

Novel Low-Dimensional Ferroelectric Materials and Devices

低维铁电薄膜是一种得到广泛研究的铁电存储器的核心材料,其利用自发极化这一本征特性来实现信息存储.铁电材料的极化方向在外加电场作用下以超快速度进行切换,切换后的电畴具有保持特性.利用该原理的新型存储技术可以实现高速、低功耗、非破坏性读取以及超高密度存储.传统铁电材料受到临界尺寸限制,即随厚度减薄到极限尺寸后材料失去铁电特性,为此发展了大量的新型二维铁电薄膜,突破了以上临界尺寸的限制,为未来集成通用存储器带来了希望.该文综述了铁电材料相关背景及研究理论;报道了低维铁电钙钛矿薄膜畴壁电流相关研究以及基于第一性原理的二维铁电材料理论研究和实验论证;阐述了基于这些新型低维铁电材料的铁电畴壁存储器,基于氧化铪的铁电场效应晶体管,以及铁电二极管的工作原理;总结了低维铁电材料及其器件这一崭新领域目前所面临的挑战,以及对未来进行了展望.

The low-dimensional ferroelectric thin films play a crucial role in studies of ferroelectric general-purpose memory,which utilizes the binary spontaneous polarization orientations to realize information storage.The polarization direction of a ferroelectric material can be switched at an ultra-high speed under an applied electric field,and the switched domain has a good retention,which enables a future new ferroelectric memory possessing high-speed and low-power operations in non-destructive reading and ultra-high-density storage.Unfortunately,the ferroelectricity in traditional materials are lost below a critical geometric size.To overcome this problem,a large number of new two-dimensional ferroelectric thin films have been developed,which provides the chance to integrate high-density ferroelectric general-purpose memories in the future.This review briefly discussed the research background and new theories of ferroelectric materials in these fields.More attention is paid on domain wall currents in low-dimensional ferroelectric perovskite films with experimental demonstrations and first-principles calculations,which enables the integration of a new ferroelectric domain wall memory.Besides this discussion,the working principles in other hafnia oxide-based ferroelectric field effect transistors and ferroelectric diodes are also described.Finally,we give current challenges and the prospects for these low-dimensional ferroelectric materials and devices.