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The present study investigates the usage of a novel natural dye derived from red algae of Morocco in dye-sensitized solar cells (DSSCs) for the first time. The main pigments responsible for sensitizing the semiconductor TiO2 coatings in the red algae were identified as phycoerythrin, carotenoid, and chlorophyll. The efficiency of a DSSC made from red algae was compared to that of a solar cell made from chlorophyll alone. The photovoltaic performance of the DSSC was evaluated through photocurrent density to photovoltage (J-V) characteristic analysis, and the efficiency was found to be 0.93%. To gain insights into its behavior, the absorbance and photoluminescence in a broad range were studied. Both absorbance and photoluminescence exhibited a broad-spectrum range. Additionally, electronic properties, such as HOMO, LUMO, energy gap, and chemical reactivity parameters, were studied using density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

This article covers selected properties of organic–inorganic thin films of hybrid perovskites with the summary formulas CH3NH3MI3, where M = Pb, Cd, Ge, Sn, Zn. The paper discusses not only the history, general structure, applications of perovskites and the basics of the theory of nonlinear optics, but also the results of experimental research on their structural, spectroscopic, and nonlinear optical properties. The samples used in all presented studies were prepared in the physical vapor deposition process by using co-deposition from two independent thermal sources containing the organic and inorganic parts of individual perovskites. Ultimately, thin layers with a thickness of the order of nanometers were obtained on glass and crystalline substrates. Their structural properties were characterized by atomic force microscopy imaging. Spectroscopic tests were used to confirm the tested films' transmission quality and determine previously unknown physical parameters, such as the absorption coefficient and refractive index. Experimental results of the nonlinear optical properties were obtained by studying the second and third harmonic generation processes and using initial sample polarization in the so-called Corona poling process. The obtained experimental results allowed us to determine the second- and third-order nonlinear optical susceptibility of the tested materials. [ABSTRACT FROM AUTHOR]

The melt-quenching technique was used to prepare strontium phosphate glasses with bismuth oxide. The impact of replacing Bi3+ with Sr2+ on density (d), molar volume (Vm), and glass transition temperature (Tg) was investigated. The FTIR spectra revealed that the structural units of the samples consisted of [BiO3], [BiO6], [PO3], and [PO4]. UV-visible spectroscopy was used to study the optical transmittance, energy band gap (Eopt), and Urbach energy (Etail). The Wemple-Didomenico model successfully described the dispersive behavior of the refractive index. Impedance spectroscopy is utilized to determine the electrical and dielectric properties. The AC conductivity followed Jonscher's universal power law, and it was observed that as the concentration of Bi2O3 increased, the frequency exponent (s) decreased. The dielectric constant (ϵ') and dielectric loss (tan δ) were found to be frequency and composition dependent. The parameters describing the dispersion of dielectric constant are obtained through the Cole-Davidson relation. [ABSTRACT FROM AUTHOR]

In this work, we explore a new experimental study of Barium oxide (BaO) thin films, fabricated using the physical vapor deposition (PVD) technique on both glass and silicon substrates. The BaO thin films have emerged as highly adaptable materials with immense potential across multiple technological domains. The investigation focuses on the morphological, optical, and electrical properties of BaO thin films to determine their potential for various applications. These films, consistently tailored to a thickness of 100 nm, exhibit exceptional optical properties, boasting an impressive transmittance rate of up to 90%. This makes them exceptionally well-suited for applications that demand superior optical transmission, such as flat-panel displays, photovoltaic devices, and various optoelectronic applications. The films' low roughness values, measured at 6.31 nm for glass-deposited films and 13.32 nm for silicone-deposited ones, underscore their uniformity, ensuring stable and precise performance control in diverse applications. Further underscoring their versatility is the wide energy gap of 2.93 eV, suggesting their potential utility in advanced optoelectronic devices that require higher energy levels. In addition to their optical prowess, BaO thin films exhibit impressive electrical resistance, measuring at 3.3 × 108 ohms, rendering them promising candidates for specialized applications, including pressure and humidity sensors, as well as electrical insulation devices. Overall, these films represent an exciting avenue for addressing specific technological needs and driving innovation in the realm of thin film technology. [ABSTRACT FROM AUTHOR]

In this work, a novel experimental investigation of photoluminescence properties of Znq2 thin films co-doped with different concentrations of DCM were performed. The thin films were successfully deposited on glass substrates with different compositions, under high vacuum, by using the vacuum evaporation technique. For all compositions, the photoluminescence was measured at room temperature and also at low temperature in a wide range from 77 to 300 K with a step of 25 K in a high vacuum. The lifetime of the sample studied in real time was also measured using the decay time technique. The results obtained confirm that the doping influences the intensity of the DCM photoluminescence and also shows a complete energy transfer occurred from Znq2 to DCM which may have shifted the photoluminescence peak from Znq2 to the orange wavelength region which is related to DCM. The lifetime of the sample studied in real time was about 4.47 ns for Znq2 and while all the other samples showed two decay time components. As a result, the doping influences the optical properties of Znq2 and makes it a potential candidate for optoelectronic applications. [ABSTRACT FROM AUTHOR]

New experimental results of morphological and optical properties of Curcuma longa dye thin film were investigated. The thin films were deposited by physical vapor deposition technique. Morphological properties were measured using atomic force microscopy technique and they show a granular structure which above there are nanotubes shapes. Photoluminescence of Curcuma longa at low temperature was investigated and discussed for the first time. The temperature effect from 77 to 300 K of Curcuma longa thin film has been shown and luminescence was strongly observed. Photoelectrochemical parameters of the dye-sensitized solar cell based on Curcuma longa have been computed via the finite element method. The power conversion efficiency is about 0.86% obtained from short circuit current, open-circuit voltage, and fill factor of 0.13 mA/cm2, 0.52 mV, and 0.83, respectively. As a result, Curcuma longa dye can be applied to dye-sensitized solar cells. [ABSTRACT FROM AUTHOR]

In this paper we investigate transmittance and reflectance spectra of multilayer hyperbolic metamaterials in the presence of strong spatial dispersion. Our analysis revealed a number of intriguing optical phenomena, which cannot be predicted with the local response approximation, such as total reflectance for small angles of incidence or multiple transmittance peaks of resonant character (instead of the respective local counterparts, where almost complete transparency is predicted for small angles of incidence and the broad-angle transparency can be observed within a range of larger angles of incidence). We believe that the observed effects may serve as a working principle in a number of new potential applications, such as spatial filtering, biosensing, or beam steering. [ABSTRACT FROM AUTHOR]

Benzonitrile derivatives (BDs) are very promising for applications in materials science, photonics, and optoelectronics due to their intriguing electronic and optical properties. This study comprehensively investigates BDs, aiming to uncover their fundamental characteristics and potential applications. Using advanced theoretical techniques like Gaussian software, it is gained unprecedented insights into the photoinduced isomerization phenomenon for all‐optical switching in these compounds. The theoretical framework clarifies molecular transition states and explores a range of properties, providing a comprehensive understanding of BDs. Empirical data on the emission properties of BDs, from fluorescence analyses in liquid solutions to light amplification in solid‐state PMMA thin films, complement the theoretical examinations. Notably, white light emission from a single benzonitrile compound is achieved, showcasing its potential for data transmission through Li‐Fi technology. Finally, the all‐optical switching phenomenon in BDs using 3rd order nonlinear optical effects is experimentally validated. This complementary and comprehensive study advances understanding of BDs and demonstrates their potential for practical applications in emerging photonic and optoelectronic technologies. [ABSTRACT FROM AUTHOR]

• HTM2 thin films were elaborated using the Physical vapor deposition method. • The characterization has been done by AFM, MEB, UV–VIS, PL spectra, and decay. • HTM2 exhibited a homogeneous surface with good absorption in the UV region. • The experimental results were validated using DFT calculations. • HTM2 can be applied as a potential HTM for perovskite solar cells. This paper presents the development of a dopant-free HTM as a thin film, utilizing carbazole (2,7) as a central building block. The deposition of homogeneous thin films of HTM2 was successfully achieved through Physical Vapor Deposition. The morphological, optical, and electrical properties of the fabricated samples were extensively studied using techniques such as Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), UV–visible spectroscopy, and Photoluminescence Technique. The AFM and SEM analyses demonstrated the uniformity and flatness of the thin film surfaces. The UV spectra results indicated that the maximum absorption spectra did not exhibit significant shifts when measured in chlorobenzene solvent, with an estimated band gap of approximately 2.96 eV. Photoluminescence spectroscopy and decay time measurements were conducted on HTM2 thin films, which revealed emission in the green-yellow region. The photoluminescence spectra of the thin films exhibited red-shifted emission bands compared to the solution, attributable to stronger π-π intermolecular interactions resulting in the closeness of the molecules in the solid state. This work finally couples the theoretical and experimental results to validate our obtained results and to get an idea about the efficiency of the cell-based HTM2. The obtained results confirmed that the investigated material can find applications in perovskite solar cells. [ABSTRACT FROM AUTHOR]

In this article, new experimental results of the morphological and optical properties of thin films of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran co-doped by 8-hydroxyquinoline zinc (Znq 2) for different concentrations were presented. The physical vapor deposition in a high vacuum was used to create the thin films on glass substrates with a thickness of 100 nm. The morphological properties of the samples were identified using the Atomic Force Microscopy (AFM) apparatus in tapping mode. TEM images show amorphous structures. The phase composition of the samples was assessed using FTIR methods. The Tauc plot approach was used to examine the measured transmittance spectra in order to estimate the energy gap. Analysis of the results showed that the co-doping of DCM thin film by Znq 2 influenced the structural and optical properties of the samples. To evaluate the experimental results found, theoretical calculations based on the maximum one-photon absorption (OPA) wavelengths of DCM and Znq 2 have been first measured through the UV–Vis spectral technique. Then, the experimental conclusions on values for DCM and Znq 2 have been compared with their corresponding simulation data procured from the time-dependent self-consistent-field (TD-SCF) computation utilizing the density functional theory (DFT) at B3LYP/6-311G(d,p) level. Besides, we have explored the first and second frontier molecular orbitals (MOs) for title compounds and their energy gaps via the DFT procedure. The calculations of maximum OPA wavelengths and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) contributions on both molecules have also been crosschecked with the results of already published data in the literature. • The co-deposition of the films of Znq 2 and DCM was prepared by vacuum evaporation. • Doping has strongly influenced the structure of the thin films. • Multiple gap values were experimentally observed in the thin films. • TDDFT/B3LYP level of theory was employed to determine the maximum OPA wavelengths and HOMO-LUMO energy gaps of Znq 2 and DCM. [ABSTRACT FROM AUTHOR]

Optical properties of Alizarin dye for dye-sensitized solar cells were performed experimentally using transmittance and photoluminescence spectroscopies and confirmed theoretically using the density functional theory. The solvent effect of photoluminescence measurement was observed, and the strongest luminescence was 1.4E7 CPS at 437 nm. A widely investigated transmittance, focusing our attention on its optical properties in the visible and near-infrared regions. Broad absorbance from 400 nm to 600 nm was shown with two maximum peaks. The electronic properties such as HOMO and LUMO levels were computed via Gaussian software, as well as the estimation of the key photovoltaic parameters such as ΔG inject, ΔG reg , |V RP |, LHE, τ and V oc equal to −1.96 eV, 1.64 eV, 1.22 eV, 0.21, 11.39 ns and 1.26 V, respectively. The theoretical absorbance calculations of Alizarin dye are in good agreement with the experimental measurement, with a shift of 9 nm for the first absorbance peak and 2 nm for the second peak. The experimental and computational results confirm that Alizarin dye can be applied as a potential sensitizer for dye-sensitized solar cells. • Broad absorbance and strong photoluminescence of Alizarin dye. • Optimized geometry calculation and electronic properties by DFT and B3LYP/6-311G**. • Correlations between theoretical results and experimental data. • Theoretical and experimental justifications for the DSSC application of Alizarin. [ABSTRACT FROM AUTHOR]