Feng Miao1
Nanjing University1
Van der Waals (vdW) heterostructures are formed by stacking layers of different 2D materials and offer possibilities to design new structures with atomic-level precision. In this talk, I will show how these heterostructures provide unprecedented opportunities to realize emerging device applications, especially in the fields of neuromorphic electronics and optoelectronics.<br/> I will first show that highly robust memristors with good thermal stability, which is lacking in traditional memristors, can be created from a vdW heterostructure composed of graphene/MoS<sub>2–x</sub>O<sub>x</sub>/graphene. With the help of <i>in situ</i> electron microscopy, we revealed the origin of good thermal stability and a possible switching mechanism.<sup>[1]</sup> We also demonstrated that artificial neuron devices and reconfigurable synaptic devices can be realized based on unique tuneable properties of various 2D materials.<sup>[2]</sup><br/> vdW vertical heterostructures can also be exploited to realize neuromorphic optoelectronic applications. We demonstrated a prototype reconfigurable neural network vision sensor that operates via the gate-tunable positive and negative photoresponses of a WSe<sub>2</sub>/BN heterostructure, and in-sensor broadband convolutional processing using a band-alignment-tuneable PdSe<sub>2</sub>/MoTe<sub>2</sub> heterostructure.<sup>[3-4]</sup> A neuromorphic vision system with brain-inspired visual perception can be further realized by networking such retinomorphic sensors with a memristive crossbar array.<sup>[5]</sup><br/> In the last part of my talk, our latest results on a scalable massively parallel computing scheme using continuous-time data representation in crossbar arrays<sup>[6]</sup> will be presented.<br/> <br/><b>References:</b><br/>[1] M. Wang, S. Cai, C. Pan, C. Wang, X. Lian, Y. Zhuo, K. Xu, T. Cao, X. Pan, B. Wang, S. Liang, J. Yang*, P. Wang*, F. Miao*, <i>Nature Electronics</i> <b>1</b>, 130 (2018).<br/>[2] C. Pan, C. Wang, S. -J Liang*, Y. Wang, T. Cao, P. Wang, C. Wang, S. Wang, B. Cheng, A. Gao, E. Liu, K. Watanabe, T. Taniguchi, F. Miao*, <i>Nature Electronics</i> <b>3</b>, 383 (2020).<br/>[3] C. Wang, S. -J Liang, S. Wang, P. Wang, Z. Li, Z. Wang, A. Gao, C. Pan, C. Liu, J. Liu, H. Yang, X. Liu, W. Song, C. Wang, B. Cheng, X. Wang, K. Chen, Z. Wang, K. Watanabe, T. Taniguchi, J. Yang*, F. Miao*, <i>Science Advances</i> <b>6</b>, eaba6173 (2020).<br/>[4] L. Pi, P. Wang, S. Liang, Peng Luo, Haoyun Wang, Dongyan Li, Zexin Li, Ping Chen, Xing Zhou*, F. Miao*, Tianyou Zhai*, <i>Nature Electronics</i> <b>5</b>, 248 (2022).<br/>[5] S. Wang, C. Wang, P. Wang, C. Wang, Z. Li, C. Pan, Y. Dai, A. Gao, C. Liu, J. Liu, H. Yang, X. Liu, B. Cheng, K. Chen, Z. Wang, K. Watanabe, T. Taniguchi, S. -J Liang*, F. Miao*, <i>National Science Review</i> <b>8</b>, nwaa172 (2021).<br/>[6] C. Wang, S.-J Liang, C. Wang, Z. Yang, Y. Ge, C. Pan, X. Shen, W. Wei, Z. Zhang, B. Cheng, C. Zhang, F. Miao*, <i>Nature Nanotechnology</i> <b>16</b>, 1079 (2021).