High-Performance Doped Silver Films: Overcoming Fundamental Material Limits for Nanophotonic Applications.
The field of nanophotonics has ushered in a new paradigm of light manipulation by enabling deep subdiffraction confinement assisted by metallic nanostructures. However, a key limitation which has stunted a full development of high-performance nanophotonic devices is the typical large losses associated with the constituent metals. Although silver has long been known as the highest quality plasmonic material for visible and near infrared applications, its usage has been limited due to practical issues of continuous thin film formation, stability, adhesion, and surface roughness. Recently, a solution is proposed to the above issues by doping a proper amount of aluminum during silver deposition. In this work, the potential of doped silver for nanophotonic applications is presented by demonstrating several high-performance key nanophotonic devices. First, long-range surface plasmon polariton waveguides show propagation distances of a few centimeters. Second, hyperbolic metamaterials consisting of ultrathin Al-doped Ag films are attained having a homogeneous and low-loss response, and supporting a broad range of high-k modes. Finally, transparent conductors based on Al-doped Ag possess both a high and flat transmittance over the visible and near-IR range.
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
Cheng
C
Zhang
School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.
Nathaniel
N
Kinsey
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
Long
L
Chen
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
Chengang
C
Ji
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.|Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, CA, 92697, USA.
Mingjie
M
Xu
School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.|Institute of Photonics and Quantum Sciences, Heriot-Watt University, SUPA, Edinburgh, Scotland, EH14 4AS, UK.
Marcello
M
Ferrera
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, CA, 92697, USA.|Department of Physics and Astronomy, University of California-Irvine, Irvine, CA, 92697, USA.
Xiaoqing
X
Pan
School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.
Vladimir M
VM
Shalaev
School of Electrical and Computer Engineering, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.
Alexandra
A
Boltasseva
Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA.
L Jay
LJ
Guo
doped silver; hyperbolic metamaterials; plasmonic waveguide; transparent conductors; ultrathin silver films