Switching of the Optical Properties of Ge2Sb2Te5 Phase Change Material in the Terahertz Frequency Region

Kotaro Makino, Kosaku Kato, Yuta Saito, Paul Fons, Alexander V. Kolobov, Junji Tominaga, Takashi Nakano, Makoto Nakajima

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A reversible insulator-to-metal transition in phase change materials is expected to be usuful for a variety of optoelectronic devices including terahertz (THz) applications. Here, we report on the phase-dependent changes in the optical properties of the thin films of Ge2Sb2Te5 (GST) phase change material. THz time domain spectroscopy measurements were carried out for amorphous and crystalline samples obtained by annealing at different temperatures and the optical properties of the GST films in the THz frequency range were characterized. It was found that the amorphous GST film was almost transparent to THz radiation due to the of absence of free carriers. On the other hand, the crystalline GST films were found to absorb THz radiation depending on the annealing temperature. The index of refraction was found to enhance with increasing annealing temperature. These properties are promising for THz wave devices such as programable amplitude modulator or plasmonic devices.

Original languageEnglish
Title of host publicationIRMMW-THz 2019 - 44th International Conference on Infrared, Millimeter, and Terahertz Waves
PublisherIEEE Computer Society
ISBN (Electronic)9781538682852
DOIs
Publication statusPublished - 2019 Sep
Externally publishedYes
Event44th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2019 - Paris, France
Duration: 2019 Sep 12019 Sep 6

Publication series

NameInternational Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz
Volume2019-September
ISSN (Print)2162-2027
ISSN (Electronic)2162-2035

Conference

Conference44th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2019
CountryFrance
CityParis
Period19/9/119/9/6

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Switching of the Optical Properties of Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub> Phase Change Material in the Terahertz Frequency Region'. Together they form a unique fingerprint.

  • Cite this

    Makino, K., Kato, K., Saito, Y., Fons, P., Kolobov, A. V., Tominaga, J., Nakano, T., & Nakajima, M. (2019). Switching of the Optical Properties of Ge2Sb2Te5 Phase Change Material in the Terahertz Frequency Region. In IRMMW-THz 2019 - 44th International Conference on Infrared, Millimeter, and Terahertz Waves [8873769] (International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz; Vol. 2019-September). IEEE Computer Society. https://doi.org/10.1109/IRMMW-THz.2019.8873769