Han Zhuokun, Chang Yu, Luo Bingcheng, Wang Shuanhu, Zhai Wei, Wang Jianyuan
School of Physical Science and Technology, MOE Key Laboratory of Materials Physics and Chemistry under Extraordinary Conditions, Northwestern Polytechnical University, Xi'an 710072, P.R. China.
ACS Appl Mater Interfaces. 2024 Apr 17;16(15):19254-19260. doi: 10.1021/acsami.4c02067. Epub 2024 Apr 3.
Recently, certain ferroelectric tunnel junctions (FTJs) exhibit non-volatile modulations on photoresponse as well as tunneling electroresistance (TER) effects related to ferroelectric polarization states. From the opposite perspective, the corresponding polarization states can be read by detecting the levels of the photocurrent. In this study, we fabricate a novel amorphous selenium (a-Se)/PbZrTiO (PZT)/Nb-doped SrTiO (NSTO) heterojunction, which exhibits a high TER of 3 × 10. Unlike perovskite oxide FTJs with a limited ultraviolet response, the introduction of a narrow bandgap semiconductor (a-Se) enables self-powered photoresponse within the visible light range. The self-powered photoresponse characteristics can be significantly modulated by ferroelectric polarization. The photocurrent after writing polarization voltages of +4 and -5 V exhibits a 1200% increase. Furthermore, the photocurrent could be clearly distinguished after writing stepwise polarization voltages, and then a multistate information storage is designed with nondestructive readout capacity under light illumination. This work holds great significance in advancing the development of ferroelectric multistate photoelectronic memories with high storage density and expanding the design possibilities for FTJs.
最近，某些铁电隧道结（FTJs）在光响应以及与铁电极化状态相关的隧道电阻（TER）效应方面表现出非易失性调制。从相反的角度来看，可以通过检测光电流水平来读取相应的极化状态。在本研究中，我们制备了一种新型的非晶硒（a-Se）/锆钛酸铅（PZT）/掺铌钛酸锶（NSTO）异质结，其表现出高达3×10的高TER。与具有有限紫外响应的钙钛矿氧化物FTJs不同，引入窄带隙半导体（a-Se）能够在可见光范围内实现自供电光响应。自供电光响应特性可通过铁电极化进行显著调制。写入+4和-5 V极化电压后的光电流增加了1200%。此外，在逐步写入极化电压后，光电流可以清晰区分，然后设计了一种在光照下具有无损读出能力的多态信息存储。这项工作对于推动具有高存储密度的铁电多态光电子存储器的发展以及扩展FTJs的设计可能性具有重要意义。
