Katarzyna Grochowska

An effective approach is proposed for fabricating surface‐enhanced Raman spectroscopy (SERS) substrates by applying the method pulsed laser deposition in open air to obtain Au and Ag nanostructures. Laser ablation is performed using nanosecond laser pulses at a wavelength of 1064 nm. At certain experimental parameters, the ablation process results in the deposition of material on the substrate, with poor adhesion to it. The morphology and chemical composition of the deposited structures are studied and discussed in detail. The SERS capability of the structures produced is evaluated by using ammonium nitrate as an analyte. The sensitivity of Ag and Au structures is also investigated using several aqueous solutions of ammonium nitrate with different concentrations. It is demonstrated that Ag structures obtained by the proposed method can detect ammonium nitrate at a concentration 20 times lower compared to the normal Raman analysis. The presented method turned out to be a simple, fast, and inexpensive way to fabricate SERS substrates that are an alternative to advanced multistep technologies.

Semitransparent perovskite solar cells (ST‐PSCs) are becoming increasingly important for applications such as tandem photovoltaics and building‐integrated photovoltaic technologies. A significant challenge in their fabrication is the damage caused by sputtering during the deposition of transparent conductive oxides (TCOs), which can harm exposed layers and degrade device performance. To tackle this issue, we develop an optimized fabrication strategy that incorporates a tin oxide (SnO ₂ ) buffer layer, effectively protecting the sensitive layer from sputtering‐induced damage during the deposition of TCOs, specifically indium in oxide (ITO), which serves as the rear electrode. The resulting ST‐PSCs achieved a record power conversion efficiency (PCE) of 21.87%. Additionally, when integrated into a four‐terminal (4T) tandem configuration with a commercial crystalline silicon (c‐Si) bottom cell, the combined device reaches an over‐efficiency of 27.15%. Beyond efficiency, these devices exhibit remarkable operational stability, achieving a T ₈₀ of 1600 h during continuous light soaking (ISOS‐L‐1) and maintaining performance for over 4000 h in outdoor conditions (ISOS‐O‐3) through an effective encapsulation technique.

Rzetelność, uczciwość, a także empatia, humor oraz nietraktowanie widzów z góry. Academia zapytała naukowców-popularyzatorów o klucz do sukcesu.

This work presents results on nanosecond laser ablation of a titanium (Ti) plate immersed in a liquid medium using the fundamental wavelength (1064 nm) of a nanosecond Nd:YAG laser system. The laser radiation was focused on the target surface as scanning was accomplished by an XY translation stage. The laser processing of the Ti targets took place in two organic liquids—liquid paraffin and diesel oil. The morphology of the structured surfaces and the structure and phase composition of the samples were studied; their dependences on the processing parameters are discussed. With both liquid media used, crack formation on the surface of the laser-treated Ti target was observed. Formation of a titanium carbide (TiC) phase was found whose properties could be tuned by varying the laser irradiation parameters. Raman measurements were utilized to analyze the carbon structure formed in the resulting coatings. The results of surface electron microscopy reveal that the thickness of the resulting coatings reached 20 µm. Some of the obtained coatings demonstrated about three times higher hardness compared to the native Ti sample. The technique proposed can be used in surface modification of materials in view of improving their mechanical properties.

Differences between photoelectrochemical and electrochemical activity were thoroughly investigated for the oxygen evolution reaction mediated by Ag₂S deposited on two types of ordered titania substrates. Titanium dioxide nanotubes were fabricated by anodization of magnetron sputtered Ti films on ITO-coated glass substrates or directly from Ti foil. Further, Ag₂S deposition on the nanotubes was carried out using successive ionic layer adsorption and reaction, known as SILAR, with 5, 25, and 45 cycles performed. Two types of nanotubes, one on transparent the other on non-transparent substrates were compared regarding their geometry, structure, optical, and electrochemical properties. It was demonstrated that the composite of Ag₂S grown on transparent nanotubes exhibits higher catalytic activity compared to Ag₂S grown on the nanotubes formed on Ti foil. The results showed that transparent nanotubes after modification with Ag₂S by 25 SILAR cycles exhibit ca. 3 times higher photocurrent under visible light illumination than non-transparent ones treated with the same number of cycles. Furthermore, transparent nanotubes after 45 SILAR cycles of Ag₂S exhibit enhanced activity towards oxygen evolution reaction with 9.3 mA cm⁻² at 1.1 V vs. Ag/AgCl/0.1 M KCl which is six times higher than titania alone on Ti foil.