Jung Ju-Hyun, Kim Seong Hun, Park Youngjun, Lee Donghwa, Lee Jang-Sik
Department of Materials Science and Engineering Pohang University of Science and Technology (POSTECH) Pohang 37673 Korea.
Division of Advanced Materials Science Pohang University of Science and Technology (POSTECH) Pohang 37673 Korea.
Adv Sci (Weinh). 2020 Jun 26;7(16):2001367. doi: 10.1002/advs.202001367. eCollection 2020 Aug.
Memory devices have been advanced so much, but still it is highly required to find stable and reliable materials with low-power consumption. Halide perovskites (HPs) have been recently adopted for memory application since they have advantages of fast switching based on ionic motion in crystal structure. However, HPs also suffer from poor stability, so it is necessary to improve the stability of HPs. In this regard, combined first-principles screening and experimental verification are performed to design HPs that have high environmental stability and low-operating voltage for memory devices. First-principles screening identifies 2D layered ABX structure as the best candidate switching layer for memory devices, because it has lower formation energy and defect formation energy than 3D ABX or other layered structures (ABX, ABX). To verify results, all-inorganic 2D layered CsPbBr is synthesized and used in memory devices. The memory devices that use CsPbBr show much better stability and lower operating voltages than devices that use CsPbBr. These findings are expected to provide new opportunity to design materials for reliable device applications based on calculation, screening, and experimental verification.
存储器件已经取得了很大的进步，但仍然非常需要找到稳定可靠且低功耗的材料。卤化物钙钛矿（HPs）最近已被应用于存储领域，因为它们基于晶体结构中的离子运动具有快速切换的优势。然而，HPs的稳定性也较差，因此有必要提高HPs的稳定性。在这方面，通过结合第一性原理筛选和实验验证来设计用于存储器件的具有高环境稳定性和低工作电压的HPs。第一性原理筛选确定二维层状ABX结构是存储器件最佳的候选开关层，因为它比三维ABX或其他层状结构（ABX、ABX）具有更低的形成能和缺陷形成能。为了验证结果，合成了全无机二维层状CsPbBr并将其用于存储器件。使用CsPbBr的存储器件比使用CsPbBr的器件表现出更好的稳定性和更低的工作电压。这些发现有望为基于计算、筛选和实验验证的可靠器件应用材料设计提供新的机会。
