Effect of Ar Gas Pressure on LSPR Property of Au Nanoparticles: Comparison of Experimental and Theoretical Studies

Microstrain effects of laser-ablated Au nanoparticles in enhancing CZTS-based 1 Sun photodetector devices

Copper zinc tin sulfide (CZTS) thin films were synthesized on soda lime glass using pulsed laser deposition (PLD) at room temperature. Introducing gold nanoparticles (AuNPs) in a sandwich structure led to increased CZTS particle size and a shift in the localized surface plasmon resonance (LSPR) peak of the AuNPs, influenced by different laser energy levels. The absorption measurements revealed intriguing behavior across the visible and near-infrared (NIR) regions, making these films appealing for 1 Sun photodetectors. Furthermore, the presence of AuNPs in the sandwich structure reduced microstrain effects, measuring 1.94 × 10-3 compared to 3.38 × 10-3 in their absence. This reduction directly enhances carrier transport, which is particularly beneficial for accelerating the performance of photodetector devices. This effect of AuNPs also contributed to higher dielectric coefficients, further improving the photodetector performance. Under 1 Sun illumination conditions, this enhancement resulted in a rapid rising time of 95.4 ms, showcasing the potential for faster photodetection.

Utilizing Gold Nanoparticle Decoration for Enhanced UV Photodetection in CdS Thin Films Fabricated by Pulsed Laser Deposition: Exploiting Plasmon-Induced Effects

UV sensors hold significant promise for various applications in both military and civilian domains. However, achieving exceptional detectivity, responsivity, and rapid rise/decay times remains a notable challenge. In this study, we address this challenge by investigating the photodetection properties of CdS thin films and the influence of surface-deposited gold nanoparticles (AuNPs) on their performance. CdS thin films were produced using the pulsed laser deposition (PLD) technique on glass substrates, with CdS layers at a 100, 150, and 200 nm thickness. Extensive characterization was performed to evaluate the thin films' structural, morphological, and optical properties. Photodetector devices based on CdS and AuNPs/CdS films were fabricated, and their performance parameters were evaluated under 365 nm light illumination. Our findings demonstrated that reducing CdS layer thickness enhanced performance concerning detectivity, responsivity, external quantum efficiency (EQE), and photocurrent gain. Furthermore, AuNP deposition on the surface of CdS films exhibited a substantial influence, especially on devices with thinner CdS layers. Among the configurations, AuNPs/CdS(100 nm) demonstrated the highest values in all evaluated parameters, including detectivity (1.1×1012 Jones), responsivity (13.86 A/W), EQE (47.2%), and photocurrent gain (9.2).

Recent Progress of Copper-Based Nanomaterials in Tumor-Targeted Photothermal Therapy/Photodynamic Therapy

Nanotechnology, an emerging and promising therapeutic tool, may improve the effectiveness of phototherapy (PT) in antitumor therapy because of the development of nanomaterials (NMs) with light-absorbing properties. The tumor-targeted PTs, such as photothermal therapy (PTT) and photodynamic therapy (PDT), transform light energy into heat and produce reactive oxygen species (ROS) that accumulate at the tumor site. The increase in ROS levels induces oxidative stress (OS) during carcinogenesis and disease development. Because of the localized surface plasmon resonance (LSPR) feature of copper (Cu), a vital trace element in the human body, Cu-based NMs can exhibit good near-infrared (NIR) absorption and excellent photothermal properties. In the tumor microenvironment (TME), Cu2+ combines with H2O2 to produce O2 that is reduced to Cu1+ by glutathione (GSH), causing a Fenton-like reaction that reduces tumor hypoxia and simultaneously generates ROS to eliminate tumor cells in conjunction with PTT/PDT. Compared with other therapeutic modalities, PTT/PDT can precisely target tumor location to kill tumor cells. Moreover, multiple treatment modalities can be combined with PTT/PDT to treat a tumor using Cu-based NMs. Herein, we reviewed and briefly summarized the mechanisms of actions of tumor-targeted PTT/PDT and the role of Cu, generated from Cu-based NMs, in PTs. Furthermore, we described the Cu-based NMs used in PTT/PDT applications.

A New Approach to the Formation of Nanosized Gold and Beryllium Films by Ion-Beam Sputtering Deposition

Thin films of beryllium and gold that are several tens of nanometers thick were obtained, for the first time, on silicon and quartz substrates by the ion-beam method with tenfold alternation of deposition and partial sputtering of the nanosized metal layer. Scanning electron and atomic force microscopy indicate the predominant lateral growth of nanosized metal layers along the substrate surface. Optical spectra indicate the suppression of the localized plasmon resonance. The growth of the film occurs under the influence of the high-energy component of the sputtered metal atoms’ flux. The main role in the formation of the nanosized metal film is played by the processes of the elastic collision of incident metal atoms with the atoms of a substrate and a growing metal film. Metal films that are obtained by the tenfold application of the deposition–sputtering of a nanoscale metal layer are characterized by stronger adhesion to the substrate and have better morphological, electrical, and optical characteristics than those that are obtained by means of direct single deposition.

Photothermal Catalytic Degradation of Lomefloxacin with Nano Au/TiO2

With the fast development of intensive poultry and aquaculture, the consumption of antibiotics has ever been increasing. Absorbed or metabolized antibiotics usually enter the water environment in the form of active drugs and metabolites, which can enhance the resistance of pathogenic microorganisms and even cause serious water pollution. Considering the bacteriostatic activity of antibiotics, the main biological method used to treat organic waste water has limited efficiency. Herein, we prepared Au/TiO2 for the efficient photocatalytic degradation of lomefloxacin (LOM) antibiotic wastewater. Based on the characteristics of prepared Au/TiO2, the short–wavelength light can be converted into photogenerated carriers with TiO2 support and the long–wavelength light can be converted into heat, likely due to the localized surface plasmon resonance effect of Au, synergistically promoting the LOM degradation. This study not only demonstrates that Au/TiO2 is an efficient photocatalyst for LOM degradation, but also further indicates the effectiveness of photocatalytic technology in the treatment of antibiotic wastewater.