Tunable chiroptical response of chiral system composed of a nanorod coupled with a nanosurface

• Published in: Applied surface science 2019-02, Vol.467-468, p.684-690
• Main Authors: Ullah, Hamad, Qu, Yu, Wang, Tiankun, Wang, Yongkai, Jing, Zhimin, Zhang, Zhongyue
• Format: Article
• Language: English
• Subjects: Artificial chiral structure; Circular dichroism; Glancing angle deposition; Nanosurface; Plasmonics
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.10.198

[Display omitted] •Chiral plasmonic nanostructures (CPNs) are fabricated by glancing angle deposition method using EB evaporator.•The proposed system consists of Ag nanorod coupled with an Ag nanosurface, separated by an in-between SiO2 layer.•CPNs exhibit LSPR and strong chiroptical responses in visible to near-infrared region.•The generated CD is easily tunable by changing the width of the nanosurface coupled with the nanorod.•An apparent enhancement and redshift of CD spectra is observed when the width of the nanosurface increases. Artificially engineered chiral plasmonic nanostructures (CPNs) have attracted considerable attention and have been widely studied in the recent decades because of their distinguishing optical properties. Researchers have focused on noble metal nanostructures, because of their strong chiroptical response in visible and near-infrared regions. In this study, a system of a nanorod coupled with a nanosurface, which were both made of silver, was proposed. Glancing angle deposition (GLAD) method was used to fabricate CPNs. The fabricated CPNs generated a strong circular dichroism (CD) signal under visible and near-infrared light illumination. A high peak was observed at approximately 600 nm, and an increasing trend of the CD intensity with a redshift was confirmed when the area of the nanosurface was increased. The generated CD could be tuned easily by changing the area of the nanosurface with an active control of the vapor deposition angle (glancing angle of the substrate) in the GLAD method.