Ionic-Gated Perovskite Quantum Dots/Graphene Heterojunction Synaptic Transistor with Bipolar Photoresponse for Neuromorphic Computing

• Xiaoying He, Minghao Xu, Shilin Liu, Kun Wang, Bowen Cao, Lan Rao, and Xiangjun Xin
• received 12/19/2023; accepted 03/28/2024; posted 03/29/2024; Doc. ID 516207
• Abstract: By combining good charge transport property of graphene and excellent photo-carrier’s generation characteristic of perovskite quantum dots (PQDs), we propose and demonstrate an ionic-gated synaptic transistor based on CsPbBr3 QDs/graphene heterojunction for bipolar photoresponse. Controlling potential barrier of the CsPbBr3 QDs/graphene heterojunction can promote the separation of photogenerated carrier pairs and effectively retard their recombination. Using the ionic-gate-tunable Fermi level of the graphene and the pinning effect of PQDs, bipolar photocurrents response corresponding to the excitatory and inhibitory short-term and long-term plasticity are realized by adjusting the negative gate bias. A series of synaptic functions including logic operation, Morse code decoding, the optical memory and electrical erasure effect, and light-assisted re-learning have also been demonstrated in an optoelectronic collaborative pathway. Furthermore, the excellent optical synaptic behaviors also contribute to the handwritten font recognition accuracy of ~ 95% in artificial neural network simulations. The results pave the way for the fabrication of the bipolar photoelectric synaptic transistors and bolster new directions in the development of future integrated human retinotopic vision neuromorphic system.