In this work, Cu-doped (3-In2S3 thin films with Cu concentrations of 0%, 4%, 6%, and 8% were deposited by vacuum thermal evaporation, and their structural, microstructural, electrical transport, and thermistor properties were systematically investigated. The primary objective is to elucidate the influence of Cu doping on charge carrier dynamics across both DC and AC conduction regimes and to correlate these mechanisms with thermistor performance. X-ray diffraction (XRD) analysis confirms the formation of single-phase (3-In2S3 for all films, demonstrating successful Cu incorporation without secondary phase formation. Energy-dispersive X-ray (EDX) analysis further validates the compositional homogeneity of the films. The effects of Cu doping on charge transport behavior were examined through DC and AC conductivity measurements over a wide temperature range. DC electrical measurements reveal semiconducting behavior governed by thermally activated charge transport, with activation energies indicating enhanced carrier localization upon Cu incorporation. The conduction mechanisms were analyzed using small polaron hopping, Greaves hopping, and Mott variable-range hopping models, providing a comprehensive description of the transport processes in different temperature regimes. Frequency-dependent AC conductivity spectra exhibit distinct dispersive regions, and the temperature dependence of the frequency exponent supports the applicability of the Quantum Mechanical Tunneling for the undoped (3-In2S3 and the Nearly Constant Loss model for the doped films. Scaling analysis reveals successful superposition of conductivity spectra for all compositions, confirming the validity of the time-temperature superposition principle, while Summerfield scaling indicates weak Coulomb interactions and temperatureindependent microscopic dynamics. Key thermistor parameters, including maximum temperature coefficient of resistance, thermistor constant (3, sensitivity factor a, and stability factor, were extracted and show systematic enhancement with increasing Cu content. These results establish a direct correlation between Cu- induced modifications in charge carrier dynamics and improved thermistor performance. This work provides new insight into the interplay between doping, transport mechanisms, and sensing properties in (3-In2S3 thin films, highlighting their potential for high-temperature thermistor applications.

In this work, Cu-doped β-In2S3 thin films with Cu concentrations of 0%, 4%, 6%, and 8% were deposited by vacuum thermal evaporation, and their structural, microstructural, electrical transport, and thermistor properties were systematically investigated. The primary objective is to elucidate the influence of Cu doping on charge carrier dynamics across both DC and AC conduction regimes and to correlate these mechanisms with thermistor performance. X-ray diffraction (XRD) analysis confirms the formation of single-phase β-In2S3 for all films, demonstrating successful Cu incorporation without secondary phase formation. Energy-dispersive X-ray (EDX) analysis further validates the compositional homogeneity of the films. The effects of Cu doping on charge transport behavior were examined through DC and AC conductivity measurements over a wide temperature range. DC electrical measurements reveal semiconducting behavior governed by thermally activated charge transport, with activation energies indicating enhanced carrier localization upon Cu incorporation. The conduction mechanisms were analyzed using small polaron hopping, Greaves hopping, and Mott variable-range hopping models, providing a comprehensive description of the transport processes in different temperature regimes. Frequency-dependent AC conductivity spectra exhibit distinct dispersive regions, and the temperature dependence of the frequency exponent supports the applicability of the Quantum Mechanical Tunneling for the undoped β-In2S3 and the Nearly Constant Loss model for the doped films. Scaling analysis reveals successful superposition of conductivity spectra for all compositions, confirming the validity of the time-temperature superposition principle, while Summerfield scaling indicates weak Coulomb interactions and temperature-independent microscopic dynamics. Key thermistor parameters, including maximum temperature coefficient of resistance, thermistor constant β, sensitivity factor α, and stability factor, were extracted and show systematic enhancement with increasing Cu content. These results establish a direct correlation between Cu- induced modifications in charge carrier dynamics and improved thermistor performance. This work provides new insight into the interplay between doping, transport mechanisms, and sensing properties in β-In2S3 thin films, highlighting their potential for high-temperature thermistor applications.

Three p-tert-butylthia calix[4]arene derivatives containing p-toluenesulfonyl groups at the lower rim and characterized by their high electron density and aromatic content were synthesized. These were analyzed using FT-IR, NMR, elemental analysis, and optical absorption spectra. Thin films of the compounds were created via thermal evaporation and assessed through UV-Visible spectroscopy, with dielectric and dispersion properties compared to existing literature. The results reveal that the band energy gaps for compounds 2-4 are 3.70, 3.23, and 2.90 eV, respectively. The increased conjugation and high absorption coefficients observed make these materials promising for optoelectronic applications. The films exhibited extraordinarily high nonlinear optical properties, with refractive index and third-order nonlinear susceptibility approximately 400 times greater than those of chalcogenide and oxide materials, highlighting their suitability for nonlinear optical systems. Furthermore, our findings are consistent with density functional theory (DFT) calculations using the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) approach at the 6-311G(d,p) level, validating the theoretical predictions with experimental data.

Thin-film-based solar cell research is a critical focus for materials scientists due to its rapid growth as a sustainable energy solution. Indium sulfide (In2S3) has emerged as a promising material in the development of CdTe-based photovoltaic devices. In2S3; an inorganic two-dimensional semiconductor, has attracted significant interest for its potential in thin-film photovoltaics, photoelectrochemical cells, and other energy-related applications. Despite this growing interest, the commercial form of In2S3 remains under characterized. In this study, we systematically investigate the physical characteristics of graphene oxide (GO) incorporated into powdered β-phase In2S3. The samples were analyzed using X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and impedance spectroscopy (IS). XRD analysis confirmed that all samples were polycrystalline and crystallized in the tetragonal β-phase, with a reduction in crystalline size as the GO content increased. XPS analysis indicated the formation of oxygen vacancies without significant changes in elemental composition. TEM images showed that GO was well dispersed across the surface of In2S3, resulting in a reduced particle size. Electrical characteristics, measured via impedance spectroscopy, showed semiconducting behavior with a decrease in resistance as temperature increased, indicating enhanced conductivity. The results suggest that GO-doped In2S3 pellets could serve as promising materials for photovoltaic systems, especially as optical windows in solar cells. The study offers valuable insights into the role of GO in modulating the properties of In2S3 and highlights its potential for optimizing materials used in solar applications.

Isatin derivatives were condensedby refluxing ethanol with thiazolobenzimidazole, yielding four linked 2-oxoindolin-3-ylidene)benzo [4,5]imidazo-[2,1-b]thiazol-3(2H)-ones. Thermal evaporation was used to deposit thin films of the produced 2-oxoindolin-3-ylidene)benzo [4,5]imidazo-[2,1-b]thiazol-3(2H)-one derivatives, which underwent thorough analysis employing UV-Vis and NIR spectroscopy. The spectral profiles of these materials were scrutinized with respect to their absorption, dielectricconstants, and dispersion propertiesand compared to previously published data. The current samples were suitable for application in optoelectronic devices, particularly as solar-absorbent materials, due to their high absorption coefficient (alpha > 10(5)cm(-1)) at a solar maximum wavelength (lambda = 500 nm). Additionally, their band and optical gap energies have been determined as 3.60, 3.56, 2.53, and 3.24 eV. The conclusions drawn from geometry optimization and nonlinear optical (NLO) calculations, performed using density functional theory (DFT) with the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) approach at the 6-311G (d,p) level, further support these findings.

High-performance titanium dioxide (TiO 2 ) thin films were successfully produced and deposited on a circular glass substrate using the spin coating process at room temperature. The deposited films were subjected to annealing at temperatures of 300, 800, 900, 1000 and 1100 °C to investigate the temperature-dependent changes in their physical characteristics. Analysis techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet–visible transmittance spectroscopy, were employed to examine the properties of the TiO 2 films. The SEM images revealed that the films were homogeneous, consistent and dense, exhibiting minimal presence of pores and microcracks. AFM scans demonstrated that the film surfaces were uniformly smooth, with a roughness ranging from approximately 0.52 to 2.85 µm. Additionally, SEM analysis indicated that the films were crack-free, homogeneous and composed of fine grains with an average size of approximately 50 nm. The UV spectral results unveiled important optical changes in the films. The Urbach energy exhibited an increase from 1.47 to 2.5 eV, while the direct band gap energy showed a decrease from 3.90 to 3.03 eV. Regarding the hydrophilicity of the TiO 2 films, the sample annealed at 300 °C displayed the lowest water contact angle among all tested samples. However, the hydrophilicity of anatase TiO 2 thin films increased when subjected to annealing temperatures between 400 and 800 °C. Conversely, the presence of the rutile phase resulted in a reduction in hydrophilicity when the annealing temperature ranged from 900 to 1100 °C. It was found that by using annealing, thin spin coated TiO 2 films will be more uniform and transparent. These results demonstrate the suitability of the obtained TiO 2 films for use in solar cells, further supporting their potential for practical applications.

Inorganic lead-free metal halide perovskites are being rigorously explored as a substitute for organic lead-based materials for various energy device applications. Germanium as a replacement for lead has been proven to give exemplary results theoretically, and there have been promising results. The current work presents the investigation of CsGeI3 (CGI) polycrystals grown using a solution-free melt-growth technique with low-cost precursors. A soak-ramp profile was designed to synthesize polycrystalline powders, which were evaluated for stability. X-ray diffraction and Raman spectroscopy analysis suggest the formation of CsGeI3 perovskite powders, matching the reported literature. Diffuse reflectance spectroscopy measurements showed the bandgap of the polycrystals to be around 1.6 eV. A prominent photoluminescence peak was obtained at 767 nm. The powders were examined using thermogravimetric analysis to assess the thermal degradation pathways. The as-grown inorganic perovskite polycrystals were relatively stable during storage under ambient conditions. Theoretical studies were also carried out to support the experimental data. Calculations were performed with different approximations, including local density approximation (LDA), generalized gradient approximation (GGA), and Heyd–Scuseria–Ernzerhof (HSE) approximation, out of which the HSE approximation yielded the most accurate results that matched the experimental findings. Moreover, for the CGI device with Ag electrodes simulated using SCAPS-1D software, highest incident photon-to-electron conversion efficiency was observed. The obtained optical and structural properties indicate the suitability of the synthesized CsGeI3 perovskite polycrystals for photovoltaic applications, specifically solar cells and light-emitting diodes.

High-performance organometallic materials based on phthalocyanine (Pc) thin films with nickel, copper, manganese and silicon were deposited onto glass substrates using spin-coating technique at room temperature. The physical properties of the films were characterized to evaluate the influence of the dopant metal on their performance. Various analytical techniques, including X-ray diffraction analysis (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and ultraviolet–visible transmittance spectroscopy, were employed to investigate the characteristics of the prepared films. For every sample, the produced films showed amorphous structure and crystallization. Analyses using XPS were done. It was discovered that there are three peaks in the composite C1s X-Pc signal, which is relevant to the interpretation of the main C1s signal. Analysis of SEM images revealed a uniform, dense, and homogeneous structure in the films, with minimal pores and microcracks. Optical analysis showcased remarkable visible-range optical absorption and an optical direct band gap ranging from 3.15 to 3.72 eV, along with exceptional transmission properties. The comprehensive exploration of the physical and optical characteristics of these phthalocyanine films positions the material as a promising candidate for advancements in solar cell technology, paving the way for potential breakthroughs in innovative and efficient solar energy applications.

Perovskite materials play a significant role in oxygen sensors due to their fascinating electrical and ionic conductivities. The sol-gel technique was employed to prepare various compositions of B-site-deficient Fe-doped SrTiO3 (iron-doped strontium titanate) or Sr(Ti0.6Fe0.4)1-x O3-δ , where x = 0.01, 0.02, and 0.03. The XRD results revealed that the principle crystalline phase of the samples was the cubic perovskite structure. The B-site deficiency improved the ionic and total conductivities of Sr(Ti0.6Fe0.4)1-x O3-δ . A small polaron conduction behavior occurred in the total electrical conductivity. The XPS results showed that the oxygen vacancy value decreased with the rise in the amount of B-site deficiencies. A lower B-site deficiency amount could produce more oxygen vacancies in the lattice but resulted in the ordering of vacancies and then lower ionic conductivity. The aging behavior was caused by the ordering of oxygen vacancies and resulted in a degeneration of electrical features under a long service time. Conversely, augmentation of the B-site deficiency amount inhibited the tendency for the ordering of oxygen vacancies and then promoted the electrical performance under a long usage time. The conduction mechanism of oxygen ions through oxygen vacancies was thoroughly investigated and discussed. The current study presents a feasible approach to ameliorate the physical features of conductors through doping the B-site of the perovskite layer with Fe, which would be a fruitful approach for numerous applications, including oxygen sensors and fuel cells anodes.

Renewable energy can be harnessed from wastewater, whether from municipalities or industries, but this potential is often ignored. The world generates over 900 km3 of wastewater annually, which is typically treated through energy-consuming processes, despite its potential for energy production. Environmental pollution is a most important and serious issue for all and their adulterations to the aquatic system are very toxic in very low concentrations. Photocatalysis is a prominent approach to eliminating risky elements from the environment. The present study developed Zinc oxide (ZnO), Copper-doped Zinc oxide (CuZnO), and Cobalt-doped Zinc oxide (CoZnO) nanostructures (NSs) by facile hydrothermal route. The crystalline and structural stability of the synthesized nanostructures were evident from XRD and FESEM analysis. Metal, and oxygen bond and their interaction on the surfaces and their valency were explored from XPS spectra. Optical orientations and electron movements were revealed from UV-Visible analysis. After 100 min exposure time with 1 g of catalyst concentration 60%, 70%, and 89% of dye degraded, for dye concentration (5 mg/L to 50 mg/L), the huge variation observed (70% to 22%), (80% to 16%), (94% to 10%). The highest photodegradation rate (55%, 75%, 90%) was observed on pH~12 using ZnO, CoZnO, and CuZnO respectively. Photodegradation of methylene blue confirmed the largest surface area, rate of recombination, photo-excited charge carriers, photo-sensitivity range, and radical generations of ZnO, CuZnO, and CoZnO. The present study, therefore, suggested that CuZnO would be preferred to produce nanomaterials for industrial wastewater treatment like methylene.

In this work, we have clarified and studied in depth the complicated alternating current (AC) mechanisms for the Ruddlesden Popper (RP) Oxide Ba2SnO4, which is an ionic material presenting high compatibility with the modified OLPT model MOM. This study allows filtering the difference between a piezoelectric and not piezoelectric material having both the MOM model. In this work, we show the significant impact of the stability of the Tendency to the Activation Energy (TAE) with the frequency variation (in the active band) in the appearance and the persistence of the ionic transporter of its acoustic lattice vibration: phonion. This latter is fundamental in ensuring the MOM mechanism in both materials (piezoelectric or not). Moreover, we have highlighted the microscopic reverse piezoelectric behavior and the role played by both the value and the resistance of the tendency to the activation energy (TAE) to reveal an eventual piezoelectric phenomenon.

Transition metal oxide shows some exceptional optical and electronic properties explore in recent investigations. In this context, the current study presents first principal and experimental investigations of pure and Zr doped CeO2 thin films. The simulations were performed using density functional theory based Wien2k-code with PBE-GGA approximation. The uniform and well-distributed granular thin films were grown for experimental investigations. The simulations and experimental results show a good resemblance in outcomes. The density of states predicts the p-d hybridization between Ce and O atoms while band structure reduce with Zr incorporation in CeO2 structure. Crystallographic analysis reveals the presence of crystalline cubic phase with space-group 225-F-m3m in thin films. Experimentally observed bandgap follows the reducing trend with Zr incorporation as predicted by simulations data and found as 2.38 eV for pure CeO2 and 1.51 eV for 6.25% Zr doping content. Optical parameters were recorded as a function of photon energy which strongly influenced by Zr concentration. The sharp increase in optical absorption and real part of dielectric constant in Zr containing composition makes these materials more efficient and favorable for photovoltaic and optoelectronic applications.

The recent advancements in thin film photovoltaic technologies have spurred the demand for raw materials that are abundant and non-toxic. This need has prompted the investigation of Cu 2 AlSnS 4 (CATS) thin films synthesized through the single source Vacuum Thermal Evaporation process and the impact of substrate type on their quality. In this study, various nonconductive substrates were used. The resulting samples were analyzed using various techniques to evaluate their structural, morphological, and optical characteristics. The films produced showed high quality and desirable morphology. Among the substrates used, the film deposited on ITO exhibited the best crystallinity based on the structural analysis. Additionally, the average grain size, as determined and was found to be 281.09 nm. The surface roughness of the ITO-deposited film was to be 8.25 nm through atomic force microscopy measurements. X-ray photoelectron spectroscopy analysis indicated that the samples contained nearly all the necessary components. An ideal band gap of 1.55 eV was observed for the ITO-deposited film based on optical analysis, which also showed a maximum absorption coefficient of 10 4 cm −1 in the visible region. These findings suggest that the fabricated CATS films are suitable for use as absorber layers in solar cells.

Abstract Cu2AlSnS4 (CATS) was generated through directly fusing of extremely pure elements. Powder show a tetragonal crystal system belongs to the space group Fd3m and the CATS film displays narrow and weak diffraction peaks corresponding to the CZTS structure of pure kesterite without secondary phase. The surface appearance and chemical content films exposed their homogenous character. The optical analysis displayed good visible-range optical absorption and optical direct band gap of 1.30–1.65 eV with excellent transmission. CATS showed high photocatalytic efficacy to degrade methylene blue (MB) completely under UV-light irradiation. These results will open the opportunity for using this new material as talented candidate in solar cells and removing organic pollutants from aqueous solutions.

In this work, novel nanocomposites (NCs) were fabricated via in situ-chemical oxidative polymerization process. For the purpose of examining their physical and chemical properties, the synthesized samples were examined utilizing a variety of analytical techniques. XRD, TEM, SEM, electrical and dielectric studies confirm the presence of copolymer P(Py-co-OT) and reveal that MFe 2 O 4 @P(Py-co-OT)NCs exhibited a core–shell structure. The Poly (Pyrrole-co-o-toluidine) possessed the highest activation energy and the lowest conductivity. Moreover, the incorporation of MFe 2 O 4 into copolymer enhances the conductivity. Impedance analysis emphasizes the contribution of grain boundaries on transport properties. A relationship between the polarization effect and the dielectric behavior was found. An enhancement on the dielectric constant εʹ and the dielectric loss ε″ was noticed with the embedding of spinel ferrites into copolymer. Results obtained suggest that this binary material has a promise for use in energy conversion applications.

Sol-gel spin coating was employed to deposit titanium dioxide (TiO2) and Cu-TiO2 composites on glass substrates. Cu was utilized as a dopant in varying amounts. The structural, morphological, optical, and dielectric characteristics of the produced samples were evaluated using a variety of techniques. XRD analysis was used to confirm the anatase (TiO2) phase's existence. After adding Cu(NO3)2.3(H2O) to TiO2, it was observed that Cu atoms were mostly distributed on the TiO surface, resulting in a decrease in the particle size, as revealed by the TEM images. Raman Spectroscopy and FTIR analysis indicates the expansion of the lattice TiO2 with Cu amount and the formation of vibrating Ti-O-Ti bonds respectively. With increasing dopants, spherical nanoparticles begin to form and orient themselves to aggregate, as shown in the AFM's noticeable shift in roughness. The UV-vis spectroscopy revealed a shift of the absorption peak toward visible range that signified an increase in the bandgap after doping. The theoretical study using quantum espresso ab initio simulation and DFT + U correction were used to derive the electronic band gap energy values which are consistent with our experimental results.

In this study, a novel formulation for the production of Sn 2 S 3 powder from solid reaction is proposed, with tin and sulfur source serving as the key precursor compounds. Single thermal evaporation source was used to produce Sn 2 S 3 thin films. The samples were identified and measured using XRD, XPS, OM, SEM, AFM, Raman spectroscopy, and UV–vis spectroscopy. Sn 2 S 3 film characteristics are influenced by the transparent substrates that are used. The choice of substrate affects the sample surface's homogeneity and RMS roughness. The optical band gap energy was determined in the range of (2.22–2.75) eV range for direct transition. The outcomes of this research are applicable to photovoltaic and optoelectronic devices.

High-performance of TiO2 nanoparticles (NPs) thin films were synthesized using spin coating technique deposited on a glass substrate. The effect of the several layers of films which have formed is studied on the structure, morphology, surface, optical and electrical characteristics. From the analysis using X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), raman spectroscopy, ultraviolet–visible spectrophotometer and impedance spectroscopy the obtained results show that anatase crystalline is obtained after annealing at 400 °C from TiO2 (NPs) in powder form. The surface of samples is uniform and the rms roughness is dependent on the number of layers and varied within the range 25.40–43.81 nm. The optical bandgap energy is obtained in the 2.9–3.2 eV range of multilayer TiO2 (NPs) thin films. The electrical characteristic analyzed as a function of temperature and frequency demonstrated a semiconducting behavior, and showed a decreased of resistance with the increase of temperature. The obtained activation energy based on impedance analysis is about 0.7 eV. It is showed that TiO2 deposited on the SnO2 glass substrate has anatase crystalline structure and their optical bandgap energy is about 3.0 eV. Electrical analysis shows semiconductor behavior over the explored temperature range from 400 °C.

This study utilized the vacuum thermal evaporation method to successfully grow Cu 2 AlSnS 4 (CATS) and Cu 2 Al x Fe 1−x SnS 4 films on glass substrates, with a focus on the impact of doping on the structural, morphological, optical, and dielectric characteristics of the deposited films. The obtained samples were identified and measured using XRD, SEM, EDX, AFM, and UV–Vis–NIR spectroscopy. X-Ray diffraction analysis confirmed a single phase of CATS with a crystalline nature and average crystallite size of 16.60–42.19 nm. Scanning electron microscope and atomic force microscopy analysis showed a non-spherical agglomeration formation and surface roughness, respectively. According to energy-dispersive X-ray spectroscopy examination, iron (Fe) was detected for doped samples in the CATS structure. Optical testing revealed that the band gap, the refractive index and extinction coefficient significantly changed as more iron was added. These results suggest that Fe doping in the Fe-cationic site of the CATS thin film can be systematically regulated to achieve desirable characteristics as an absorber for solar cells.