For the first time, organic light-emitting diodes (OLEDs) based on bis(8-hydroxyquinoline) zinc with a styryl group (ZnStq) dispersed in poly(N-vinylcarbazole) matrix (ZnStq_R:PVK, where R = H, Cl, OCH₃) were fabricated. The ZnStq_R:PVK films made via the spin-coating method were used as the active layer in these devices. The produced OLEDs showed strong electroluminescence with yellow emissions at 590, 587 and 578 nm for the ZnStq_H:PVK, ZnStq_Cl:PVK and ZnStq_OCH₃:PVK, respectively. For all the studied thin films, the main photoluminescence emission bands were observed between 565 and 571 nm. The OLED with the ZnStq_OCH₃:PVK layer with a narrow electroluminescence spectrum was found to have sufficient color purity to produce ultra-high-resolution displays with reduced power consumption (full width at half maximum of 59 nm, maximum brightness of 2244 cd/m² and maximum current efficiency of 1.24 cd/A, with a turn-on voltage of 6.94 V and a threshold voltage of 7.35 V). To characterize the photophysical properties of the active layer, the ZnStq_R:PVK layers samples were additionally deposited on glass and silicon substrates. We found that the obtained results predestine ZnStq_R:PVK layers for use in the lighting industry in the future.

The aim of the study was to present the influence of various styrylquinoline (StQ) substituents on the luminescence, structural, and optical properties of StQ-containing copolymers. StQ-containing copolymers were synthesized by free-radical thermoinitiated polymerization. The calculations of the copolymerization ratios for the obtained copolymers were based on the basis of the integrated peak areas of the ¹H NMR spectra in CDCl₃. The luminescence measurements show that the change in the nature of the electron-donating and electron-withdrawing of the substituent shifts the emission band to longer wavelengths and causes a transition from blue fluorescence to green or yellow and orange (or even white), regardless of the electronic nature of the introduced substituent group. The structural properties were measured by Fourier-Transform Infrared (FTIR) and Raman spectroscopies. For all of the compounds, we observed similarities in the bands in FTIR and Raman measurements. The optical parameters were obtained from the absorbance measurements. Additionally, Scanning Electron Microscopy (SEM) was used to study the surface topography of the thin layers on the glass substrate. The SEM images confirm that we obtained smoother layers for two copolymers. The computational Density Functional Theory (DFT) analysis fully supports the beneficial features of the analyzed systems for their applications in optoelectronic devices. Based on the obtained results, it can be concluded that all of the studied styrylquinolines are promising materials for applications in organic light-emitting diodes (OLEDs). However, COP1 with an OCH₃ donor substituent possess a wider luminescence band, and its layer is smoother and more transparent.

Tris(8-hydroxyquinoline)aluminium with poly(N-vinylcarbazole) (Alq 3:PVK) or polystyrene sulfonate (Alq 3:PSS) were deposited by spin-coating on glass and silicon substrates. SEM measurements show that relatively smooth thin films were obtained. Fourier transform infrared measurements were performed to confirm the composition of the samples. The optical properties of thin films containing Alq 3:PVK and Alq 3:PSS were characterised using absorption spectroscopy and spectroscopic ellipsometry. It was found that the absorption spectrum of Alq 3:PVK is characterised by four bands, while for Alq 3:PSS only three bands are visible. The photoluminescence of the studied thin layers shows a peak with a maximum at about 500 nm. Additionally, cyclic voltammetry of Alq 3 is also presented. Theoretical density functional theory calculations provide the insight into the interaction and nature of Alq 3:PVK and Alq 3:PSS excited states. Finally, the organic light-emitting diode (OLED) structure based on Alq 3:PVK was fabricated and showed strong electro-luminescence with a green emission at 520 nm. The results of the device show that the ITO/PEDOT:PSS/Alq 3:PVK/Ca/Al system can be useful for the production of low-cost OLEDs with Alq 3:PVK as an active layer for future lighting applications.

Flavonoids, natural organic compounds from the polyphenolic group with broad bioactive and pharmaceutical properties, are strong ligands for many metal ions. This work describes the formation of the complex between Zn(II) and morin. The synthesized compound is characterized using three analytical techniques, i.e., ¹H NMR, IR, and thermal gravimetric analysis. Importantly, the complex was successfully obtained in the form of a solid, which enables its further physicochemical and structural characterization. Physicochemical characterization of the Morin-Zn complex was performed by steady-state and time-resolved spectroscopy. The absorption spectrum of the complex contains two main bands at ca. 407–415 nm and ca. 265 nm, and the complex emits yellow-green light with higher intensity than the free ligand. In the next step, morin and zinc complex were dispersed in a PMMA (poly (methyl methacrylate)) polymer matrix, and respective thin layers were produced. The studied thin films were deposited on silicon substrates by using the spin-coating method and characterized by X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM), Spectroscopic Ellipsometry (SE), UV-VIS spectroscopy, and photoluminescence (PL). The absorption of thin layers showed, similarly to solutions, the presence of two transitions: π→π* and n→π*, and a bathochromic shift for the morin-zinc complex compared to morin. The photoluminescence of the complex thin film showed two bands, the first in the range of 380–440 nm corresponding to PMMA, and the second with a maximum at 490 nm, derived from the synthesized compound.

Bis(8-hydroxyquinoline) zinc dispersed in a poly(N-vinylcarbazole) matrix (Znq2:PVK) was characterised for its possible use as an active layer in organic light-emitting diodes. The composition and morphology of Znq2:PVK thin films deposited on quartz substrates was analysed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and confocal microscopy. Optical properties of the films were characterised by absorption spectroscopy and photoluminescence and explained on the basis of calculated molecular properties of gas phase Znq2, N-vinylcarbazole pentamer, and molecular models for the Znq2:PVK interface. FTIR measurements of the Znq2:PVK film revealed the presence of water, likely due to the formation of Znq2-dihydrate during the fabrication process. Water could be removed by annealing films at 130 °C for 1 h and the annealed films showed better photoluminescence in the Znq2 emission region. Finally, two diodes with an ITO/PEDOT:PSS/Znq2:PVK/Al structure were fabricated, where in the second one, the ITO/PEDOT:PSS/Znq2:PVK layers were annealed at 130 °C. The first diode was characterised by a maximum brightness of about 83 cd/m2 and a current efficiency of 0.12 cd/A, while the diode whose structure was annealed had a maximum brightness of about 219 cd/m2 and a current efficiency of 0.26 cd/A.

Division of Surface Science was established in 2021 as a result of its separation from the Department of Physics. Its research initially focused on the design and fabrication of metallic and dielectric thin films with tailored properties. Particular attention was also given to the analysis of their microstructures and optical characteristics. For this purpose, various deposition techniques were used, including physical vapour deposition (PVD) and spin coating. The samples were characterised using a range of techniques, including atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal optical microscopy (COM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), four point probe (4PP) method, spectrophotometry, and Raman spectroscopy. In parallel, chemometric methods were developed and applied to the analysis of experimental data. In subsequent years, the scope of research was expanded to include the synthesis of hybrid nanostructures incorporating diatom biosilica matrices, as well as materials synthesised via green chemistry approaches. Experimental studies confirmed the antibacterial properties of these materials. At the same time, research on the nanostructures was directed towards advanced analytical techniques, such as nanostructure-assisted laser desorption/ionization (NALDI) and surface-enhanced Raman spectroscopy (SERS). Furthermore, the scope of research conducted at the Division of Surface Science was expanded to include studies of functional proteins. The use of small-angle X-ray scattering (SAXS) enabled experiments with unattainable conditions using conventional sources. These studies focused on the structural characterisation of proteins exhibiting antibacterial and anticancer properties. The Division of Surface Science is currently a highly interdisciplinary team, bringing together diverse expertise to advance next-generation materials.