Structural and dielectric properties of ion beam deposited titanium oxynitride thin films

Transition Metal Nitrides Are Heating Up the Field of Plasmonics

“…57 However, increasing the oxygen content can increase the resistivity of the films and decrease the plasma frequency as the material becomes less metallic. 58,59 Studies performed on ZrN and ZrO x N y films showed that increased oxygen content can result in a large number of interstitial defects and makes the film dielectric; however, incorporation of very low amounts of O can actually lead to a higher carrier concentration and more metallic films than ZrN. 60 The film deposition conditions heavily influence the structural properties and chemical composition of the nitride films, and it is important to choose them carefully to yield plasmonic films with desired properties.…”

“…For most nitrides, metal-rich films exhibit higher carrier concentrations (10 21 to 10 22 cm –3 ) and films change from metallic to dielectric as the stoichiometry is varied from metal-rich to nitrogen-rich (Figure A). ,,, Increasing the metal content has also been shown to result in a shift of the SPR frequency and zero-crossover of the real part of permittivity (i.e., when the permittivity goes from a positive to negative value) to higher energies (Figure B). ,, Incorporation of oxygen can lead to novel optical properties: tunable double zero-crossover (i.e., the real permittivity is equal to zero at two different frequencies) was exhibited in Ti oxynitride films (Figure C) and may be useful in the preparation of metasurfaces or generation of nonlinear optical devices . However, increasing the oxygen content can increase the resistivity of the films and decrease the plasma frequency as the material becomes less metallic. , Studies performed on ZrN and ZrO x N y films showed that increased oxygen content can result in a large number of interstitial defects and makes the film dielectric; however, incorporation of very low amounts of O can actually lead to a higher carrier concentration and more metallic films than ZrN . The film deposition conditions heavily influence the structural properties and chemical composition of the nitride films, and it is important to choose them carefully to yield plasmonic films with desired properties.…”

High-Performance Titanium Oxynitride Thin Films for Electrocatalytic Water Oxidation

“…The present study has focused on the synthesis of TiN x O y thin films with varying x and y and the study of their performance in water splitting for oxygen evolution. The overpotentials for oxygen evolution reaction (OER; 4OH – = O 2 + 2H 2 O + 4e – ) realized for these films are in the range of 320 to 290 mV (at 10 mA/cm 2 ) which are among the lowest values reported for metal alloys, oxynitrides, and oxide systems, designed using extrinsic as well as intrinsic approaches. ,,, The materials design via the extrinsic approach is generally based on increasing the loading capacity of the electrocatalysts via defect engineering and/or surface modification, while the intrinsic approach is based on exploring novel materials with an enhanced electroactivity. − The improvement in the electrocatalytic behavior of TiNO thin films is explained based on the enhanced number of electrochemically active sites realized by the substitution of anionic N sites by O and a favorable alignment of valence band with respect to the redox potential of electrolyte medium. , These findings are of significant importance in light of water electrolysis to produce fossil-free fuels for the development of environmentally friendly power sources. , Although there are some reports on the electrocatalytic activity of TiNO system, the majority of the reports are focused on the TiNO system in the polycrystalline bulk form. ,− The significance of TiNO thin film research arises from better possibilities in precisely controlling the orientation, crystallinity, composition, grain size, and grain distribution, which are well-known to critically affect the film’s properties. ,,,− The TiNO material system in thin film form has also a strong potential for integration with technologically important substrates such as silicon and sapphire due to the small mismatch in lattice constants and thermal expansion coefficients. , …”

“…The simplicity of the synthesis and the embodiment of myriads of unique properties in TiN and TiO 2 place these two compounds among the most widely studied and used materials. After the work of Honda and Fujishima, TiO 2 has become a paradigm material in surface science and catalysis. − TiN exhibits an unusual combination of covalent, metallic, and ionic properties: ultrahardness (close to that of the diamond), high thermal conductivity, high electrical conductivity (higher than that of Ti), and even low- temperature superconductivity. − Several Ti-based oxynitrides (TiN x O y , abbreviated as TiNO) compounds, intermediate between metallic TiN and insulating TiO 2 , have gained enormous scientific and engineering attention recently due to progressive and favorable change in their properties, opening the doors for many applications. ,,,− Oxynitride stabilities in air and moisture are greater than those of the pure nitrides but have smaller bandgap than those of comparable oxides. ,− There is no isostructural phase between TiN and TiO 2 . However, TiN is isostructural with rock-salt TiN 0.5 O 0.5 (obtained with 50% substitution of N by O in TiN). ,, The rock-salt structures of TiN and TiN 0.5 O 0.5 are shown in Figure .…”

Effects of assisting ions on the structural and plasmonic properties of ZrN x thin films

“…The physical properties of IBAD films can be modified by the assisting ions in the deposition process. Ion beam modification has been used in many fields, and we had studied its application on the plasmonics of TiN x thin films [23][24][25][26]. In this study, the structure and plasmonic properties of IBAD-ZrN x thin films are investigated.…”