Unexpected ultraviolet plasmonic properties of Ge2Sb2Te5: Exploration through double Tauc–Lorentz model
Abstract
Plasmonic materials have driven nanophotonic advancements, with ultraviolet (UV) functionality and dynamic reconfigurability emerging as critical needs. This work addresses these needs by investigating the UV optical properties of Ge2Sb2Te5 (GST-225), a prototypical phase-change material. Spectroscopic ellipsometric analysis reveals that precise descriptions of UV dielectric functions of GST-225 require a double Tauc–Lorentz (DTL) model, uncovering an additional resonance at 6–8 eV. Density functional theory (DFT) calculations trace the dual oscillators in the DTL model to two distinct interband transitions. The two oscillators associated with resonant bonding give rise to broadband plasmonic properties spanning visible to extreme-ultraviolet wavelengths for GST-225, which is an unusual trait among UV plasmonic materials. The plasmonic performances are further substantiated by finite element simulations and electron energy loss spectroscopy (EELS) measurements. This study establishes GST-225 as a promising candidate for dynamically tunable UV photonic devices while broadening the scope of phase-change material applications to UV adaptive optics, sensing, and nanoscale light manipulation.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (15)
Haodong Zhong
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Xiaofeng Zhao
Xiaotian Xue
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Yunhan Hu
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Yuxue Yang
Fei Yang
Bohan Shan
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Yuanhao Zheng
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Tongzhou Xu
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Zhengyuan Zhao
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,
Kang Sun
Key Lab of Biomass Energy and Material, Jiangsu Province; Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Institute of Chemical Industry of Forest Products
Wei Luo
Rong Yu
Weipeng Wang
School of Life Science and Technology
Zhengjun Zhang
The Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University 1 , Beijing 100084,