Conductive metallic filaments dominate in hybrid perovskite-based memory devices

电导金属细丝主导的杂化钙钛矿基存储器（英文）

Organic-inorganic hybrid perovskites (OHPs) are well-known as light-absorbing materials in solar cells and have recently attracted considerable attention for the applications in resistive switching memory. Previous studies have shown that ions can migrate to form a conductive channel in perovskites under an external voltage. However, the exact resistance mechanism for Ag or halogens which dominate the resistive behavior is still controversial. Here, we demonstrate a resistive switching memory device based on Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/fluorine doped tin oxide (FTO). The migration of Ag cations and halide anions is demonstrated by energy dispersive X-ray spectroscopy (EDS) after the SET process (positive voltage on Ag). By comparing the I-V behavior of the Au-based devices, it is clear that the conductive channel formed by Ag is the main factor of the switching characteristics for Ag-based devices. Meanwhile, by controlling the appropriate SET voltage, two kinds of resistance characteristics of the analog switch and threshold switch can be realized in the Ag-based device. As a result, it may be possible to implement both data storage and neuromorphic computing in a single device.

有机-无机杂化钙钛矿(OHPs)作为太阳能电池中的光吸收材料备受重视,并且在电阻开关(RS)存储器的应用中引起了广泛关注.以前的研究表明,在外电场作用下钙钛矿中的离子能够发生迁移并形成导电通道.然而,主导其阻变行为的是Ag还是卤素仍然存在着争议.本文中,我们研究了一种基于Ag/FA0.83MA0.17Pb(I0.82Br0.18)3/FT0(掺氟的氧化锡)的电阻开关存储器.在开启过程(在Ag电极端施加正向扫描电压)完成后,我们通过EDS(能最色散X射线谱)发现了银离子和卤素离子的迁移.并通过对比基于Au电极器件的电流-电压特征曲线,发现由Ag形成的导电通道是影响Ag基器件开关特性的主要因素.同时,通过控制合适大小的开启电压,基于Ag电极的电阻开关器件实现了模拟开关和阈值开关两种不同的阻变开关特性.因此,在未来有可能在单个器件中同时实现数据存储和神经形态计算两种功能.