Melting-free integrated photonic memory with layered polymorphs
Date
2024-01-31
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Nanophotonics
Abstract
Chalcogenide-based nonvolatile phase change materials (PCMs) have a long history of usage, from bulk disk memory to all-optic neuromorphic computing circuits. Being able to perform uniform phase transitions over a subwavelength scale makes PCMs particularly suitable for photonic applications. For switching between nonvolatile states, the conventional chalcogenide phase change materials are brought to a melting temperature to break the covalent bonds. The cooling rate determines the final state. Reversible polymorphic layered materials provide an alternative atomic transition mechanism for low-energy electronic (small domain size) and photonic nonvolatile memories (which require a large effective tuning area). The small energy barrier of breaking van der Waals force facilitates low energy, fast-reset, and melting-free phase transitions, which reduces the chance of element segregation-associated device failure. The search for such material families starts with polymorphic In2Se3, which has two layered structures that are topologically similar and stable at room temperature. In this perspective, we first review the history of different memory schemes, compare the thermal dynamics of phase transitions in amorphous-crystalline and In2Se3, detail the device implementations for all-optical memory, and discuss the challenges and opportunities associated with polymorphic memory.
Description
This article was originally published in Nanophotonics. The version of record is available at: https://doi.org/10.1515/nanoph-2023-0725. © 2024 the author(s), published by De Gruyter, Berlin/Boston. This work is licensed under the Creative Commons Attribution 4.0 International License.
This research was featured in UDaily on 04/15/2024, available at: https://www.udel.edu/udaily/2024/april/tingyi-gu-national-science-foundation-career-optical-memory/
Keywords
nonvolatile memories, phase transition, layered polymorphs, integrated photonics
Citation
Ullah, Kaleem, Li, Qiu, Li, Tiantian and Gu, Tingyi. "Melting-free integrated photonic memory with layered polymorphs" Nanophotonics (2024). https://doi.org/10.1515/nanoph-2023-0725