Laterally Modulating Carrier Concentration by Ion Irradiation in CdO Thin Films for Mid‐IR Plasmonics
[1];
[2];
[1];
[3];
[4];
[5];
[6];
[7];
- Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
- Mechanical Engineering Vanderbilt University Nashville TN 37212 USA, Photonics Initiative, Advanced Science Research Center City University of New York New York NY 10031 USA
- School of Physics and Astronomy University of Southampton Southampton SO17 1BJ UK, Sensorium Technological Laboratories Nashville TN USA
- Department of Nuclear Engineering University of New Mexico Albuquerque NM 87131 USA, Center for Integrated Nanotechnology Sandia National Laboratories Albuquerque NM 87185 USA
- Center for Integrated Nanotechnology Sandia National Laboratories Albuquerque NM 87185 USA, Department of Nuclear Engineering University of Tennessee Knoxville TN 37916 USA
- School of Physics and Astronomy University of Southampton Southampton SO17 1BJ UK, Sensorium Technological Laboratories Nashville TN USA, Istituto di Fotonica e Nanotecnologie – Consiglio Nazionale delle Ricerche (CNR) Milano 20133 Italy
- Mechanical Engineering Vanderbilt University Nashville TN 37212 USA, Sensorium Technological Laboratories Nashville TN USA
Abstract This report demonstrates tunable carrier densities in CdO thin films through local ion irradiation, providing lateral control of mid‐IR optical properties. Ion‐solid interactions produce donor‐like defects that boost electron concentrations from the practical minimum of 2.5 × 10 19 cm −3 to a maximum of 2.5 × 10 20 cm −3 by metered ion exposure. This range is achieved using He, N, Ar, or Au ions at 1–2.8 MeV; when normalized by displacements per atom, all ion species produce comparable results. Since CdO is well‐described by the Drude model, irradiation‐tuned carrier densities directly alter the infrared dielectric function, and in turn, mid‐infrared optical properties. Further, it is demonstrated that by combining irradiation with traditional lithography, CdO films expose to ions in the presence of 3‐µm thick, patterned photoresist exhibit lateral carrier density profiles with ≈400‐nm resolution. Scanning near‐field optical microscopy reveals sharp optical interfaces with almost no companion contrast in surface morphology, microstructure, or crystallinity. Finally, CdO lateral homostructures supporting surface plasmon polaritons (SPPs) are demonstrated whose dispersion relation can be tuned through periodic patterning in a monolithic platform by simple nanofabrication. Numerical simulations show these polaritons result from strong coupling between excitations at CdO plasma frequencies and SPPs supported by the platinum substrate.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- NONE; NA0003525
- OSTI ID:
- 2474995
- Journal Information:
- Advanced Optical Materials, Journal Name: Advanced Optical Materials Journal Issue: 30 Vol. 12; ISSN 2195-1071
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
Similar Records
Effect of tellurium doping on the structural, optical, and electrical properties of CdO
Quantification and impact of nonparabolicity of the conduction band of indium tin oxide on its plasmonic properties