Lee SangMyeong, Kim Hyojung, Kim Dong Hoe, Kim Won Bin, Lee Jae Myeong, Choi Jaeho, Shin Hyunjung, Han Gill Sang, Jang Ho Won, Jung Hyun Suk
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Apr 8;12(14):17039-17045. doi: 10.1021/acsami.9b22918. Epub 2020 Mar 24.
Hybrid organic-inorganic halide perovskites (HPs) have garnered significant attention for use in resistive switching (RS) memory devices due to their low cost, low operation voltage, high on/off ratio, and excellent mechanical properties. However, the HP-based RS memory devices continue to face several challenges owing to the short endurance and stability of the HP film. Herein, two-dimensional/three-dimensional (2D/3D) perovskite heterojunction films were prepared via a low-temperature all-solution process and their RS behavior was investigated for the first time. The 2D/3D perovskite RS devices exhibited excellent performance with an endurance of 2700 cycles, a high on/off ratio of 10, and an operation speed of 640 μs. The calculated thermally assisted ion hopping activation energy and the results of the time-of-flight secondary ion mass spectroscopy demonstrated that the 2D perovskite layer could efficiently prevent the Ag ion migration into the 3D perovskite film. Moreover, we found that owing to its high thermal conductivity, the 2D perovskite can control the rupture of the Ag conductive filament. Thus, the 2D perovskite layer enhances endurance by controlling both Ag migration and filament rupture. Hence, this study provides an alternate strategy for improving endurance of HP-based RS memory devices.
有机-无机杂化卤化物钙钛矿(HPs)因其低成本、低工作电压、高开关比和优异的机械性能,在电阻式开关(RS)存储器件中的应用备受关注。然而,由于HP薄膜的耐久性和稳定性较差,基于HP的RS存储器件仍面临若干挑战。在此,通过低温全溶液法制备了二维/三维(2D/3D)钙钛矿异质结薄膜,并首次研究了其RS行为。2D/3D钙钛矿RS器件表现出优异的性能,耐久性达2700次循环,开关比高达10,工作速度为640 μs。计算得到的热辅助离子跳跃活化能以及飞行时间二次离子质谱结果表明,2D钙钛矿层能够有效阻止Ag离子迁移到3D钙钛矿薄膜中。此外,我们发现由于其高导热性,2D钙钛矿可以控制Ag导电细丝的断裂。因此,2D钙钛矿层通过控制Ag迁移和细丝断裂来提高耐久性。因此,本研究为提高基于HP的RS存储器件的耐久性提供了一种替代策略。