This PDF file contains the front matter associated with SPIE Proceedings Volume 12410, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Possible laser processes in battery manufacturing are quite diverse regarding the control of electrochemical characteristics: LIPSS on current collector surfaces are used to adjust the adhesion of composite electrodes to current collectors, laser surface patterning turns ceramic-coated separator materials into superwicking with regard to electrolyte wetting properties, and laser structuring of composite thick film electrodes is applied to generate 3D electrode architectures with shortened lithium-ion diffusion pathways. In the field of cathode thick film development, secondary particles with nanoscaled primary particles are used and ultrafast laser ablation is applied to pattern the composite electrodes to optimize the lithiumion diffusion kinetics by enlarging the active material surface with a view to reducing cell polarization, which develops at high battery power. This enables high energy batteries to be upgraded for operation at high power. In the field of anode development for electromotive vehicles, efforts are being made to develop silicon anodes in order to significantly increase the energy density. In addition, the issue of fast charging, mainly influenced by the anode architecture, is a major topic in research and industrial development. Silicon nanoparticles are used and combined with graphite particles in a binder matrix. The large volume change as a result of the lithiation of silicon during battery operation requires laser structuring of the composite electrodes in order to counteract mechanical degradation. Analogous to cathode materials, the lithium diffusion kinetics for anodes are also significantly enhanced by the applied 3D battery concept. The impact of laser structuring and modification of battery materials on the electrochemical performance with respect to the nanoscale is of considerable relevance for future applications in battery manufacturing.

Bacillus cereus (Bc) group are spore-forming bacteria that include human pathogenic strains, such as Bacillus cereus and Bacillus anthracis. Detection of Bc group spores using selective media is a laborious process that is largely dependent on the laboratory environment. We have examined the application of so-called digital photocorrosion (DIP) GaAs/AlGaAs biosensor for detection of Bacillus thuringiensis (Bt) spores. With the aptamer-based biosensing architecture, we have successfully demonstrated detection of Bt spores in the range between 10³ - 10⁵ spores/mL. The ease of operating DIP biosensors, and the potential for sensitive detection in field settings hold the promise of attractive applications of these innovative devices for monitoring the presence of Bc group spores.

The advent of functional devices based on two-dimensional (2D) materials has further intensified the interest in the latter. However, the fabrication of structures using layered materials remains a key challenge. Recently, we proposed the so-called “Laser-Induced Transfer” method (LIT), as a digital and solvent-free approach for the high-resolution and intact transfer of 2D materials’ pixels. Here, we will further highlight the versatility of LIT by reporting results on the high-quality digital transfer of graphene and MoS2. These materials have emerged in the field of nanoelectronics, sensors and photonics due to their unique optoelectronic properties, but their high-quality transfer remains a hurdle. The quality of the transferred films has been confirmed with systematic characterization based on Scanning Electron Microscopy and Raman spectroscopy, as well as mobility’s extraction. Then we will present how the laser induced transfer of these materials can be employed as a key-enabler for the demonstration of the digital deposition of graphene and MoS₂ pixels with form factors and electronic properties suitable for FETs. The presented results highlight the potential of LIT for the wafer scale integration of 2D materials, therefore fostering the wider industrial incorporation of 2D materials in electronics, optoelectronics and photonics.

Microscale selective laser sintering (μ-SLS) is a high throughput additive manufacturing (AM) technique developed at The University of Texas at Austin. It can fabricate high aspect ratio metal interconnect structures such as micro-pillar arrays for applications in semiconductor packaging. Additionally, as an AM process, μ-SLS aims to create complex 3D structures at a throughput that cannot be achieved by multi-step lithography processes.

Er³⁺-Yb³⁺ co-doped KGd₃F₁₀ cores, prepared by an ethylenediaminetetraacetic acid (EDTA)-assisted hydrothermal synthesis, and core-shell Er³⁺-Yb³⁺ KGd₃F₁₀@SiO₂ particles, prepared through Stöber method have been morphologically and optically characterized. Besides being employed in nanothermometry, both core and core-shell have also been exploited as contrast agents for photoacoustic images (PAI). Results of PAI upon excitation at 520 nm and 980 nm in the Er³⁺-Yb³⁺ core and core-shell nanoparticles in ethanol suspension are demonstrated and its biomedical applications discussed.

Photoacoustic imaging (PAI) is a rapidly growing imaging modality, which combines high contrast of optical absorption with deep penetration depth of ultrasound. When combined with endogenous contrast agents based on light-absorbing nanoparticles (NPs), PAI can visualize various biological processes and tissues. Here, we describe a simple experimental setup based on a tissue-mimicking phantom with flexible optical properties for studying photoacoustic (PA) response of NPs. Our approach is based on a polyacrylamide gel phantom with independently variable optical absorption and scattering. The phantom allows one to model and study PA response of contrast agents with diverse spatial distributions and concentrations. To demonstrate high potential of the developed experimental setup, we prepared a phantom with optical properties matching human prostate tissue and performed a PAI of laser-synthesized titanium nitride (TiN) NPs, distributed in a disk-shaped area, located 10 mm under the phantom surface. We believe that our approach will contribute the successful development of clinical PAI with NPs-based contrast agents.

Owing to particular physico-chemical properties and high biocompatibility, nanostructured silicon (Si) and germanium (Ge) present very promising materials for biomedical applications, but the fabrication of luminescent Si and Ge nanoparticles (NPs) in pure, uncontaminated, water-dispersible state is almost impossible by using conventional methods of wet-chemical synthesis. We recently showed that such a task can be solved by the elaboration of a technique of pulsed laser deposition (PLD) in gaseous medium under reduced gas pressures (0.5-10 Torr). In particular, PLD-prepared Si-based nanocrystalline layers and NPs could exhibit a photoluminescence (PL) band centered in the red- near infrared (maximum at 760 nm) spectral region (when ablated in pure He) or an intense “green-yellow” PL band centered at 580 nm (when ablated in He and N₂ mixture), which were attributed to quantum-confined excitonic states in small Si nanocrystals and a radiative recombination in amorphous oxynitride (a-SiN_xO_y) coating of Si nanocrystals, respectively. While as-prepared Ge nanocrystals exhibited a dominating photoluminescence (PL) band around 450 nm, which was attributed to defects in germanium oxide shell, a size-selected portion of relatively small (5-10 nm) Ge NPs exhibited a red-shifted PL band around 725 nm under 633 nm excitation, which could be attributed to the quantum confinement effect in small Ge nanocrystals. After milling by ultrasound and dispersing in water, all such nanocrystals and NPs can be used as efficient non-toxic markers for bioimaging. Here, we give a comparative analysis of the structural and optical properties of Si and Ge nanostructures produced by methods of PLD in He-N₂ gaseous mixtures and discuss their potential applications in bioimaging.

We present time resolved measurements on low dimensional nanomaterials like individual (6,4) single-walled carbon nanotubes and monolayers of MoSe₂ via transient interferometric scattering (TiSCAT) microscopy. For this a novel fiber laser system was developed comprising a tunable probe arm and low noise performance. The sensitivity of the measurement is demonstrated for very low excitation powers to prevent photodamage of the sample. Signal variations close to the shot-noise limit can be resolved even with low excitation powers in the order of 1 μW. In combination with the tunability of the laser system the absorption spectrum of a single SWCNT was determined.