Needle-like quantum dots effectively guide conductive filaments in hafnium-based memory devices

In this work, self-assembled needle-like quantum dots (CdSe-ZnS QDs) are used to enhance the local electric fields, and the formation/rupture of CFs happens at the QDs/HfO_x interface, greatly reducing the randomness of CFs generation. The consistency has been significantly improved. SET voltage's coefficient of variation (δ/μ) decreased from 13.8% to 6.7%, while δ/μ of low resistive state (LRS) even became as low as 1.56%. The QDs-HfO_x device can realize multi-level conductance modulation and mimic the behavior of long-term potentiation (LTP) and long-term depression (LTD). Further, The MNIST handwritten recognition dataset achieved high recognition accuracies (93.96%) for neuromorphic simulations. The device shows tremendous potential in neural networks and analog computation.