Demonstrating A 2D–0D Hybrid Optical Multi-Level Memory Device Operated By Laser Pulses

A technical paper titled “Probing Optical Multi-Level Memory Effects in Single Core–Shell Quantum Dots and Application Through 2D-0D Hybrid Inverters” was published by researchers at Korea Institute of Science and Technology (KIST), Korea University, Daegu Gyeongbuk Institute of Science and Technology (DGIST), National Institute for Materials Science (Japan), and University of Science and Technology (UST).

Abstract:

“Challenges in the development of a multi-level memory (MM) device for multinary arithmetic computers have posed an obstacle to low-power, ultra-high-speed operation. For the effective transfer of a huge amount of data between arithmetic and storage devices, optical communication technology represents a compelling solution. Here, by replicating a floating gate architecture with CdSe/ZnS type-I core/shell quantum dots (QDs), a 2D–0D hybrid optical multi-level memory (OMM) device operated is demonstrated by laser pulses. In the device, laser pulses create linear optically trapped currents with MM characteristics, while conversely, voltage pulses reset all the trapped currents at once. Assuming electron transfer via the energy band alignment between MoS₂ and CdSe, the study also establishes the mechanism of the OMM effect. Analysis of the designed device led to a new hypothesis that charge transfer is difficult for laterally adjacent QDs facing a double ZnS shell, which is tested by separately stimulating different positions on the 2D–0D hybrid structure with finely focused laser pulses. Results indicate that each laser pulse induced independent MM characteristics in the 2D–0D hybrid architecture. Based on this phenomenon, we propose a MM inverter to produce MM effects, such as programming and erasing, solely through the use of laser pulses. Finally, the feasibility of a fully optically-controlled intelligent system based on the proposed OMM inverters is evaluated through a CIFAR-10 pattern recognition task using a convolutional neural network.”

Find the technical paper here. Published July 2023. Read this related news article from Korea Institute of Science and Technology (KIST).

Ra, Hyun‐Soo, Tae Wook Kim, Derrick Allan Taylor, Je‐Jun Lee, Seungho Song, Jongtae Ahn, Jisu Jang et al. “Probing Optical Multi‐Level Memory Effects in Single Core‐Shell Quantum Dots and Application Through 2D–0D Hybrid Inverters.” Advanced Materials 35, no. 39 (2023): 2303664.