Stoichiometric engineering of chalcogenide semiconductor alloys for nanophotonic applications

• 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: 2020
• Subjects: Science::Physics; Chalcogenides; High Throughput
• Online Access: https://hdl.handle.net/10356/144736
• Institution: Nanyang Technological University

A variety of alternative plasmonic and dielectric material platforms-among them nitrides, semiconductors, and conductive oxides-have come to prominence in recent years as means to address the shortcomings of noble metals (including Joule losses, cost, and passive character) in certain nanophotonic and optical-frequency metamaterial applications. Here, it is shown that chalcogenide semiconductor alloys offer a uniquely broad pallet of optical properties, complementary to those of existing material platforms, which can be controlled by stoichiometric design. Using combinatorial high-throughput techniques, the extraordinary epsilon-near-zero, plasmonic, and low/high-index characteristics of Bi:Sb:Te alloys are explored. Depending upon composition they can, for example, have plasmonic figures of merit higher than conductive oxides and nitrides across the entire UV-NIR range, and higher than gold below 550 nm; present dielectric figures of merit better than conductive oxides at near-infrared telecommunications wavelengths; and exhibit record-breaking refractive indices as low as 0.7 and as high as 11.5.