柔性金属-有机框架薄膜电致阻变效应研究

As a new generation of information storage technology, flexibility of resistive random access memory (RRAM) will help advance the wearable devices for growth. For the time being, there are often many questions in the inorganic or organic storage materials. In particular, its mechanical property and storage performance are unideal. Besides that, the failure mechanisms of RRAM are unclear with increasing strain now, and result in the difficulty of obtaining high performance flexible RRAM by optimizing materials and device structures. In this project, we will take the key research on flexible inorganic-organic hybrid metal-organic framework (MOF) materials, research in situ the correlation of evolution behavior of electroresistance effect with carrier transport, and deformation and fracture of MOF film with increasing strain, and explore the regulatory effects of pore structure, microstructure, and electrode material on electroresistance effect and flexibility. The aim of the project is to find out the key influence factor of electroresistance effect stability and MOF flexibility, clarify strain-induced failure mechanism by first-principle calculation, finally get prototype RRAM based on MOF with stable storage performance and more mechanical property, and provide academic supports and valuable materials for the development of flexible storage technology.

作为一种新兴的存储技术，阻变随机存储器（RRAM）的柔性化有利于推动可穿戴电子设备的发展。目前而言，有机或无机阻变存储材料往往存在机械性能差或存储性能不稳定的问题，并且由于应变作用下器件失效的物理机制尚不明确，导致难以对材料或器件结构进行优化，以获得综合性能优异的柔性RRAM。本项目拟以有机-无机复合的柔性金属-有机框架（MOF）材料作为研究重点，原位研究应变作用下电致阻变效应的演变行为，及其与MOF薄膜中载流子输运以及形变断裂之间的关联规律，探索MOF的孔结构、薄膜的微结构、以及电极材料等因素对MOF薄膜电致阻变效应和柔韧性的调控作用，阐明影响MOF薄膜电致阻变效应稳定性和柔韧性的关键因素，结合第一性原理计算，澄清应变导致器件失效的物理机制。最终获得具有稳定存储特性和良好机械柔韧性的MOF阻变存储原型器件，为发展柔性存储技术提供理论和材料基础。

作为一种新兴的存储技术，阻变随机存储器（RRAM）的柔性化有利于推动可穿戴电子设备的发展。目前而言，有机或无机阻变存储材料往往存在机械性能差或存储性能不稳定的问题，并且由于应变作用下器件失效的物理机制尚不明确，导致难以对材料或器件结构进行优化，以获得综合性能优异的柔性RRAM。本项目以有机-无机复合的柔性金属-有机框架（MOF）材料MIL-53作为研究重点，利用自主研发的层层自组装生长装置首次将MIL-53制成了纳米量级厚度的薄膜，通过改变制备工艺调控了MIL-53薄膜的晶体结构和尺度，进而调控了MIL-53薄膜的柔韧性；研究了应变作用下MIL-53薄膜阻变性能的演变规律，发现生长在PDMS衬底上的MIL-53薄膜可承受10%的应变，比现有的无机材料提高了1个量级，比有机材料也提高了近1倍。但由于MIL-53与PDMS的弹性模量不匹配，大应变下也会出现分层、脱落和断裂等问题，导致器件失效。为此，进一步又研发了全PDMS的阻变器件，不仅存储性能稳定，且可随意变形，为发展柔性存储技术提供理论和材料基础。