Resistive Switching Mechanism in InP/ZnSe/ZnS Quantum Dots Based Neuromorphic Devices

Colloidal quantum dots (QDs) have emerged as a highly promising material in the resistive switching device due to their advantageous properties, such as size-dependent tunable optical bandgap, facile fabrication process, and scalability. Nevertheless, there are limited reports on QD-based memristors, and the precise resistive switching mechanism remains elusive. In this study, we investigate the resistive switching mechanism of InP/ZnSe/ZnS QD-based memristors. To unveil the type of charge carriers (electrons or holes) that are filled into the trap sites of QDs, we incorporate a thin poly(methyl methacrylate) as a blocking layer between QDs and either bottom or top electrodes. Through this strategy, we can figure out the trapped carriers into QDs as well as demonstrate a stable InP/ZnSe/ZnS QD-based synaptic devices. To emulate synaptic functionalities, long-term potentiation/depression (LTP/LTD) are verified, exhibiting low non-linearity of 0.1 and 1, respectively. Finally, a single-layer perceptron simulation is conducted using Extended Modified National Institute of Standards and Technology based on the LTP/LTD characteristics, resulting in a maximum recognition rate of 91.46%.