Chen Zhi, Sun Mingzi, Li Haohan, Huang Bolong, Loh Kian Ping
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology (ICL-2D MOST), Shenzhen University, Shenzhen518060, People's Republic of China.
College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, People's Republic of China.
Nano Lett. 2023 Feb 8;23(3):1077-1084. doi: 10.1021/acs.nanolett.2c04785. Epub 2023 Jan 25.
It is important to understand the polymorph transition and crystal-amorphous phase transition in InSe to tap the potential of this material for resistive memory storage. By monitoring layer-by-layer growth of β-InSe during molecular beam epitaxy (MBE), we are able to identify a cyclical order-disorder transition characterized by a periodic alternation between a glassy-like metastable subunit cell film consisting of < 5 sublayers (th layers = the number of subunit cell layers), and a highly crystalline β-InSe at = 5 layers. The glassy phase shows an odd-even alternation between the indium-cluster layer ( = 1, 3) and an In-Se solid solution ( = 2, 4), which suggests the ability of In and Se atoms to diffuse, aggregate, and intermix. These dynamic natures of In and Se atoms contribute to a defect-driven memory resistive behavior in current-voltage sweeps that is different from the ferroelectric switching of α-InSe.
了解InSe中的多晶型转变和晶体-非晶相转变对于挖掘这种材料在电阻式存储器存储方面的潜力至关重要。通过监测分子束外延（MBE）过程中β-InSe的逐层生长，我们能够识别出一种周期性的有序-无序转变，其特征是由小于5个亚层（th层=亚晶胞层数）组成的类玻璃状亚稳亚晶胞薄膜与5层时的高度结晶β-InSe之间的周期性交替。玻璃相在铟簇层（=1,3）和In-Se固溶体（=2,4）之间呈现奇偶交替，这表明In和Se原子具有扩散、聚集和混合的能力。In和Se原子的这些动态特性导致了电流-电压扫描中缺陷驱动的记忆电阻行为，这与α-InSe的铁电开关不同。
