Titanium nitride (TiN) is one of the most well-established engineering materials nowadays. TiN can overcome most of the drawbacks of palsmonic metals due to its high electron conductivity and mobility, high melting point and due to the compatibility of its growth with Complementary Metal Oxide Semiconductor (CMOS) technology. In this work, we review the dielectric function spectra of TiN and we evaluate the plasmonic performance of TiN by calculating (i) the Surface Plasmon Polariton (SPP) dispersion relations and (ii) the Localized Surface Plasmon Resonance (LSPR) band of TiN nanoparticles, and we demonstrate a significant plasmonic performance of TiN.

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Transition-metal nitrides (TMN) have exceptional stability, which underlies their use in various applications. Here, we study the role of N point defects on the stability of prototype TMNs using first-principles calculations. We find that distinct regimes for TMN changes relate to specific atomic-scale mechanisms, namely, diffusion of N interstitials (I(N)), of I(N) pairs, and of N vacancies. The activation of these processes occurs sequentially as the temperature is raised in a range of several hundreds of degrees, accounting for observed TMN changes under widely different conditions.

The ability to reverse the inherent tendency of noble metals to grow in an uncontrolled three-dimensional (3D) fashion on weakly interacting substrates, including two-dimensional (2D) materials and oxides, is essential for the fabrication of high-quality multifunctional metal contacts in key enabling devices. In this study, we show that this can be effectively achieved by deploying nitrogen (N2) gas with high temporal precision during magnetron sputtering of nanoscale silver (Ag) islands and layers on silicon dioxide (SiO2) substrates. We employ real-time in situ film growth monitoring using spectroscopic ellipsometry, along with optical modeling in the framework of the finite-difference time-domain method, and establish that localized surface plasmon resonance (LSPR) from nanoscale Ag islands can be used to gauge the evolution of surface morphology of discontinuous layers up to a SiO2 substrate area coverage of ∼70%. Such analysis, in combination with data on the evolution of room-temperature resistivity of electrically conductive layers, reveals that presence of N2 in the sputtering gas atmosphere throughout all film-formation stages: (i) promotes 2D growth and smooth film surfaces and (ii) leads to an increase of the continuous-layer electrical resistivity by ∼30% compared to Ag films grown in a pure argon (Ar) ambient atmosphere. Detailed ex situ nanoscale structural analyses suggest that N2 favors 2D morphology by suppressing island coalescence rates during initial growth stages, while it causes interruption of local epitaxial growth on Ag crystals. Using these insights, we deposit Ag layers by deploying N2 selectively, either during the early precoalescence growth stages or after coalescence completion. We show that early N2 deployment leads to 2D morphology without affecting the Ag-layer resistivity, while postcoalescence introduction of N2 in the gas atmosphere further promotes formation of three-dimensional (3D) nanostructures and roughness at the film growth front. In a broader context this study generates knowledge that is relevant for the development of (i) single-step growth manipulation strategies based on selective deployment of surfactant species and (ii) real-time methodologies for tracking film and nanostructure morphological evolution using LSPR.

(1 of 37)high mobility (µ) (even in amorphous phase), wide bandgap (transparent in the visible range), and the ability to be controllably doped. Importantly, they can be grown into thin films and various nanostructures with different scalable deposition techniques, including vacuum-based methods such as physical vapor deposition (PVD) [7,8] and chemical vapor deposition (CVD) [9] as well as solution-based processes such as spray [10] and spin coating. [11] Moreover, the resulting layers can be easily patterned using standard fabrication procedures and as such can be integrated into state-of-the-art processes for (opto)electronic applications. The above-mentioned capabilities have led to a plethora of applications such as switching backplanes for displays, transparent and flexible electronics, integrated circuits (ICs), photovoltaics (PVs), organic light-emitting diodes (OLEDs), capacitors, batteries, photocatalytic devices, electrochromics and memory devices, to name but a few. [8,[12][13][14] Because of their ability to be doped, their electronic properties can be tuned from dielectrics to semiconductors and conductors. This characteristic versatility has recently been exploited to stretch the range of their applications to new technological sectors, such as plasmonics in the near infrared and midinfrared spectral ranges. [12,15] One of the driving applications of metal oxides is in thinfilm transistors (TFTs) for large area electronics such as current driven optical displays and ICs. Following the early demonstrations, [16] most effort focused on the fabrication and processing of metal oxides TFTs paying particular attention to the device performance and applications. [1,5,6,17] Especially when processed over large areas, as in the case for display applications, the complexity to precisely control the device reliability and reproducibility becomes a challenging aspect of any TFT technology. To that respect, solution-based techniques progressed rapidly due to their lower cost and higher throughput compared to vacuum-based techniques. In both cases, the metal-oxide deposition has so far been limited to high processing temperatures (>250 °C) (Figure 1a) which renders the technology incompatible with inexpensive, temperature-sensitive substrates such as polymers, the material class of choice for various high throughput manufacturing techniques such as roll-to-roll (R2R) and sheet-to-sheet (S2S)Over the past few decades, significant progress has been made in the field of photonic processing of electronic materials using a variety of light sources. Several of these technologies have now been exploited in conjunction with emerging electronic materials as alternatives to conventional hightemperature thermal annealing, offering rapid manufacturing times and compatibility with temperature-sensitive substrate materials among other potential advantages. Herein, recent advances in photonic processing paradigms of metal-oxide thin-film transistors (TFTs) are presented with particular emphasis on the use of various light sour...

Nano-structuring of metals is one of the greatest challenges for the future of plasmonic and photonic devices. Such a technological challenge calls for the development of ultra-fast, high-throughput and low-cost fabrication techniques. Laser processing, accounts for the aforementioned properties, representing an unrivalled tool towards the anticipated arrival of modules based in metallic nanostructures, with an extra advantage: the ease of scalability. In the present work we take advantage of the ability to tune the laser wavelength to either match the absorption spectral profile of the metal or to be resonant with the plasma oscillation frequency, and demonstrate the utilization of different optical absorption mechanisms that are size-selective and enable the fabrication of pre-determined patterns of metal nanostructures. Thus, we overcome the greatest challenge of Laser Induced Self Assembly by combining simultaneously large-scale character with atomic-scale precision. The proposed process can serve as a platform that will stimulate further progress towards the engineering of plasmonic devices.