Fast, Multi‐Bit, and Vis‐Infrared Broadband Nonvolatile Optoelectronic Memory with MoS2/2D‐Perovskite Van der Waals Heterojunction

• Published in: Advanced materials (Weinheim) 2023-02, Vol.35 (6), p.e2208664-n/a
• Main Authors: Lai, Haojie, Lu, Zhengli, Lu, Yueheng, Yao, Xuanchun, Xu, Xin, Chen, Jian, Zhou, Yang, Liu, Pengyi, Shi, Tingting, Wang, Xiaomu, Xie, Weiguang
• Format: Article
• Language: English
• Subjects: 2D perovskite; Broadband; broadband optoelectronic memory; Charge transfer; charge‐trapping memory; Heterojunctions; Infrared radiation; Materials science; Molybdenum disulfide; Optoelectronics; Perovskites; Room temperature; van der Waals heterostructure
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202208664

Nonvolatile optoelectronic memory (NVOM) integrating the functions of optical sensing and long‐term memory can efficiently process and store a large amount of visual scene information, which has become the core requirement of multiple intelligence scenarios. However, realizing NVOM with vis‐infrared broadband response is still challenging. Herein, the room temperature vis‐infrared broadband NVOM based on few‐layer MoS2/2D Ruddlesden–Popper perovskite (2D‐RPP) van der Waals heterojunction is realized. It is found that the 2D‐RPP converts the initial n‐type MoS2 into p‐type and facilitates hole transfer between them. Furthermore, the 2D‐RPP rich in interband states serves as an effective electron trapping layer as well as broadband photoresponsive layer. As a result, the dielectric‐free MoS2/2D‐RPP heterojunction enables the charge to transfer quickly under external field, which enables a large memory window (104 V), fast write speed of 20 µs, and optical programmable characteristics from visible light (405 nm) to telecommunication wavelengths (i.e., 1550 nm) at room temperature. Trapezoidal optical programming can produce up to 100 recognizable states (>6 bits), with operating energy as low as 5.1 pJ per optical program. These results provide a route to realize fast, low power, multi‐bit optoelectronic memory from visible to the infrared wavelength. The unique organic/inorganic alternating chain structure of 2D Ruddlesden–Popper perovskite enables the combination of the advantages of floating gate and charge trap memories to achieve fast, multi‐bit, and vis‐infrared broadband nonvolatile optoelectronic memory.