Low‐Power Phase Transition of Chalcogenide Glass Using Au Nanoparticle Plasmon Resonance. Issue 6 (13th January 2020)

• Record Type: Journal Article
• Authors: Cao, Tun; Liu, Kuan; Lu, Li; Liu, Jianxun; Liu, Yan Jun; Qin, Kai Rong; Chui, Hsiang Chen; Simpson, Robert E.
• Is Part Of: Advanced optical materials. Volume 8:Issue 6(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-13
• Subjects: mid‐infrared -- phase‐change materials -- surface‐enhanced Raman scattering -- surface plasmon resonance -- tunable; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.201901570
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Chalcogenide materials are attractive for all‐photonic phase‐change memories owing to their large optical contrast between amorphous and crystalline structural phases. However, high‐power heating pulses are required to switch these structural phases, which can limit the cyclability. To reduce power, Au nanoparticles (NPs) are embedded in a typical chalcogenide phase‐change material, Ge2 Sb2 Te5 (GST). Raman analysis shows that a GST film crystallizes at a low optical power of 2 mW, which is almost 10 times lower than that of materials not embedded with NPs. This lower power is owing to the enhanced light absorptance through the strongly localized surface plasmon resonance (LSPR) of the Au NPs. The Au NPs embedded in the GST film scatter light at λ = 587 nm, which is close to Au NP's LSPR of ≈535 nm. Laser light at 532 nm is used to measure Raman scattering from the Au–GST system. The Raman scattering is enhanced by a factor 12 compared with a bare GST film. This study indicates that the GST film–Au NP system is suitable for high‐speed, low‐power, phase‐change memory and for a new type of tunable surface‐enhanced Raman scattering substrate. Abstract : The employment of Au nanoparticles (NPs) can significantly reduce operation power and time necessary to reach the temperature for Ge2 Sb2 Te5 (GST) crystallization and reamorphization. This is due to the enhanced light absorptance through strongly localised surface plasmon resonances of Au NPs. It indicates that the GST film–Au NP system is suitable for high‐speed and low‐power phase change memory.