Compositionally controlled plasmonics in amorphous semiconductor metasurfaces

• Main Authors: Piccinotti, Davide, Gholipour, Behrad, Yao, Jin, Macdonald, Kevin F., Hayden, Brian E., Zheludev, Nikolay I.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2019
• Subjects: Semiconductor Materials; DRNTU::Science::Physics; Metamaterials
• Online Access: https://hdl.handle.net/10356/83143; http://hdl.handle.net/10220/47571
• Institution: Nanyang Technological University

Amorphous bismuth telluride (Bi:Te) provides a composition-dependent, CMOS-compatible alternative material platform for plasmonics in the ultraviolet-visible spectral range. Thin films of the chalcogenide semiconductor are found, using high-throughput physical vapor deposition and characterization techniques, to exhibit a plasmonic response (a negative value of the real part of relative permittivity) over a band of wavelengths extending from ~250 nm to between 530 and 978 nm, depending on alloy composition (Bi:Te at% ratio). The plasmonic response is illustrated via the fabrication of subwavelength period nano-grating metasurfaces, which present strong, period-dependent plasmonic absorption resonances in the visible range, manifested in the perceived color of the nanostructured domains in reflection.