title: Dysprosium-doped cadmium oxide as a gateway material for mid-infrared plasmonics.
abstract: The interest in plasmonic technologies surrounds many emergent optoelectronic applications, such as plasmon lasers, transistors, sensors and information storage. Although plasmonic materials for ultraviolet-visible and near-infrared wavelengths have been found, the mid-infrared range remains a challenge to address: few known systems can achieve subwavelength optical confinement with low loss in this range. With a combination of experiments and ab initio modelling, here we demonstrate an extreme peak of electron mobility in Dy-doped CdO that is achieved through accurate 'defect equilibrium engineering'. In so doing, we create a tunable plasmon host that satisfies the criteria for mid-infrared spectrum plasmonics, and overcomes the losses seen in conventional plasmonic materials. In particular, extrinsic doping pins the CdO Fermi level above the conduction band minimum and it increases the formation energy of native oxygen vacancies, thus reducing their populations by several orders of magnitude. The substitutional lattice strain induced by Dy doping is sufficiently small, allowing mobility values around 500 cm(2) V(-1) s(-1) for carrier densities above 10(20) cm(-3). Our work shows that CdO:Dy is a model system for intrinsic and extrinsic manipulation of defects affecting electrical, optical and thermal properties, that oxide conductors are ideal candidates for plasmonic devices and that the defect engineering approach for property optimization is generally applicable to other conducting metal oxides.
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Edward
authors: E
authors: Sachet
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Christopher T
authors: CT
authors: Shelton
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Joshua S
authors: JS
authors: Harris
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Benjamin E
authors: BE
authors: Gaddy
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Douglas L
authors: DL
authors: Irving
authors: Department of Mechanical Engineering and Materials Science and Department of Electrical Engineering, Duke University, Durham, North Carolina 27708, USA.
authors: Stefano
authors: S
authors: Curtarolo
authors: Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.
authors: Brian F
authors: BF
authors: Donovan
authors: Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.
authors: Patrick E
authors: PE
authors: Hopkins
authors: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors: Peter A
authors: PA
authors: Sharma
authors: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors: Ana Lima
authors: AL
authors: Sharma
authors: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors: Jon
authors: J
authors: Ihlefeld
authors: Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Stefan
authors: S
authors: Franzen
authors: Department of Materials Science, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors: Jon-Paul
authors: JP
authors: Maria