稀土镍基钙钛矿氧化物半导体材料的氢致相变及在电子器件中的应用

Rare earth nickelates (ReNiO3) compounds shows dramatic changes in physical properties when experiencing the metal-insulator transitions (MIT), which provides extensive opportunities for designing electronic devices such as metal-oxide-semiconductor field-effect transistor (MOSFET). Apart from temperature induced the MIT properties similar to the case of VO2, the MIT of ReNiO3 can be also triggered by hydrogen atmosphere or proton doping, which has been reported in recent years from 2014-2015. This hydrogen induced MIT can result in the changes in resistivity reversibly over 5 orders of magnitudes, which is expected to be rather valuable for making electronic devices such as MOSFET. As a result, the hydrogen induced MIT of ReNiO3 arouses extensive attentions within the field of MIT. The present project aims at growing ReNiO3 (Re=Sm, Nd, Eu) thin films in electronic level using both pulsed laser deposition and magnetic sputtering. Based on the thin film growth, the fundamental issues, such as properties, mechanisms and kinetic processes during the hydrogen induced MIT will be mainly investigated experimentally. By further combining the experiment results with the theoretical calculations, the diffusion equations, which describe the hydrogen diffusion during the hydrogen induced MIT, will be established. From the application aspect, new MOSFET devices will be designed based on the principle of hydrogen induced MIT of ReNiO3. The structure and performance of as-designed MOSFET will be further optimized by adjusting the properties of each layer of functional materials as well as their interfaces.

稀土镍基钙钛矿氧化物半导体（ReNiO3）发生金属-绝缘体相转变过程中的物理性能的突变，在设计制备功能电子器件方面具有可观的应用价值。除具有与VO2材料类似的温致相变特性外，ReNiO3所特有的氢致相变特性于2014-2015年间被发现。通过氢致相变可在室温下引发ReNiO3电阻率超过五个数量级的可逆变化，为设计制备MOSFET等电子器件提供了广阔的思路。本研究通过脉冲激光沉积、磁控溅射两种方法实现电子级ReNiO3（Re=Sm, Nd, Eu）薄膜材料的生长。从实验角度系统研究氢致相变性能、机理、动力学过程等基础科学问题，并结合理论计算建立氢元素在ReNiO3中的扩散方程。从应用角度，深入挖掘ReNiO3的氢致相变在制备功能电子器件中的价值，基于栅极电场调控氢元素分布而触发ReNiO3氢致相变的原理制备新型金属氧化物半导体场效应晶体管，通过材料与界面调节优化其器件结构与工作性能。

近5年来，亚稳相稀土镍基氧化物电子相变半导体氢致电子相变的发现，为设计制备基于氢致电子相变效应的非易失性仿生神经元强关联逻辑器件、海洋电场探测、生物质探测等新器件与新应用开辟了新的探索方向。本项目主要围绕亚稳相稀土镍基氧化物电子相变强关联半导体材料与器件的研究方向，从亚稳相稀土镍基氧化物薄膜材料生长、温致金属绝缘体相变特性调控、氢致电子相变特性调控与机理研究、强关联电子器件的制备与潜在应用等方面开展了全面的研究。申请人突破了亚稳相稀土镍基氧化物电子相变薄膜材料生长中的技术瓶颈，实现了多稀土组元稀土镍基氧化物薄膜材料的有效生长；在此基础上，利用核反应共振探测法等技术实现了氢致相变前后稀土镍基氧化物薄膜材料中氢元素的定量分析，并修正了该体系材料氢致相变机理；最后，申请人发现并发展了基于稀土镍基氧化物电子相变材料体系的热敏-热电复合效应、宽温区低温段NTCR热敏电阻效应、Delta-温区阻变效应等新功能特性，并探索其器件应用。.项目共发表文章19篇，其中包括Matter, Nature Communications, Advanced Materials, Materials Horizons, Advanced Functional Materials等高水平期刊；申请发明专利12项。