Properties Of Sol Research Articles

Investigation of the Effects of Acid Content and Annealing on the Properties of Nanostructured TiO2 Sol

Titanium dioxide (TiO2) sol was prepared using tetrabutyl titanate as a precursor via an acid catalyzed sol-gel process. Investigation of the effects of acid content and annealing on the properties of nanostructured TiO2 materials. The influence of acid content on the sol density, viscosity, stability and particle size were studied and based on the kinematic viscosity data, Gibbs energies of activation for viscous flow (ΔG*) were also calculated. Furthermore, the prepared samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and ultraviolet-visible (UV-Vis) spectrophotometer. The results showed that the increase of acid content nearly had no obvious influence on the chemical structure of TiO2 sol. With the increase of annealing temperature, titanium dioxide changes from amorphous phase to crystalline phase, anatase coexists with rutile at 600 °C, sample absorbance increases, and the edge of UV-Vis spectra shows red shift. Ti-O-Ti bond is the main structure of TiO2 sol, and the formed TiO2 molecule has linear structure.

Changes in Spectral Properties of Aqueous Silver Sols Induced by Complexation on the Surface of Nanoparticles

The interaction of Ag+ ions existing on the surface of silver nanoparticles with complexing agents, such as ammonia, ammonium thiocyanate, and sodium thiosulfate, has been studied. Both the presence of complexing agents in the initial reaction mixture and their introduction into preliminarily synthesized sols of silver nanoparticles lead to a small shift of the absorption maximum toward long wavelengths and its considerable broadening. In both cases, there is a correlation of the absorption band width with the logarithm of formation constants of corresponding silver complexes. This can be evidence of analogous chemical processes that occur on the surface of nanoparticles. The surface complexation is of interest both for a fundamental understanding of the interaction nature and in the applied aspect for the determination of complexing agents in aqueous systems.

Luminescence Properties of Sol–Gel Derived Ceramic GdNbхTa1 –хO4 and YNbхTa1 –хO4 Solid Solutions

GdNbхTa1 –хO4 and YNbхTa1 –хO4 (x = 0–1) ceramic samples have been prepared by a sol–gel process, and the luminescence properties of the solid solutions have been studied under UV excitation. The results demonstrate that even a relatively small amount of tantalum (x = 0.9) in GdNbхTa1 –хO4 leads to a sharp increase in the luminescence intensity related to Nb4+–O– centers, which exceeds the luminescence intensity in the GdNbO4 and GdTaO4 individual compounds by a factor of 3–6.5. The luminescence signal in the YNbхTa1 –хO4 solid solutions exceeds that in the YNbO4 and YTaO4 end-members at any Nb : Ta ratio, owing to energy transfer between Nb4+–O– and Ta4+–O– emission centers.

Biofluid sampler: A new gateway for mail-in-analysis of whole blood samples

The current study reports the development of a novel biofluid sampler (BFS) which is capable of sampling and sample preparation of whole blood without converting it into plasma or serum. The sampler can retain a whole blood sample from 10 to 1000 µL. Although the device shares the same working principle of dried blood spot (DBS) cards, it eliminates most of the technological shortcomings of DBS cards such as low maximum sample volume (~50 µL), sample inhomogeneity due to haematocrit, and poor physical adsorption driven analyte retention by incorporating sol–gel derived high efficiency, multi-functional sorbents on cellulose fabric substrate. The performance of BFS was tested via “Mail-in-Analysis” using three non-steroidal anti-inflammatory drugs (NSAIDs, ketoprofen, carprofen and diclofenac) as the test compounds. Human whole blood samples were fortified with the test compounds and sampled on conventional DBS cards and biofluid samplers (BFSs) in the USA. After drying the blood samples at room temperature, the samples were shipped to Italy for chromatographic analysis. The analytes were back-extracted from the DBS cards and BFSs using methanol and subsequently analysed using a short Symmetry C18 column (75 × 4.6 mm, 3.5 µm). Acetonitrile (ACN) and PBS (30 mM; pH = 2.5) were used as the mobile phases and the elution was performed under isocratic conditions. Compared to the classical dried blood spot cards (DBS), BFSs offer better performance in retaining the selected NSAIDs under conventional postal shipment. By substantially expanding the sampling capacity, eliminating most of the shortcomings of classical DBS cards and exploiting the better materials properties of sol–gel based functional sorbents, BFSs offer a new and profoundly simplified approach for whole blood sampling and analysis and is expected to change the current practice of blood analysis, allowing accurate quantitative analyses either in a local laboratory (on site) or using mail-in-analysis (off site) without compromising the quality of bioanalytical data.

Study on microstructural and electro-optical properties of sol–gel derived pure and Al/Cu-doped ZnO thin films

In this study, pure and doped ZnO thin films were prepared by sol–gel-based method and their electro-optical properties were investigated. For doping process, 1 at. % Al and Cu was incorporated in ZnO solution separately, and the thin films were prepared by dip coating method. The microstructure and morphology of calcined ZnO, Al-doped ZnO, and Cu-doped ZnO thin films were evaluated and compared by using various techniques X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and field emission scanning electron microscopy (FESEM). Results showed that nanostructured ZnO thin films with cross-linked nanoparticles (NPs) were formed, and the size of ZnO NPs increased with the Al and Cu doping. It was also found that the substitution and interstitial of Al and Cu dopants caused the instability of ZnO crystal structure and generation of extra point defects. Photoluminescence (PL) properties indicated that the dopants incorporation causes the decline of the PL intensity and the shift of the localized energy states of electrons and holes to lower energy levels. Evaluation of thin films in the UV–Vis range demonstrated that the transparency increased (>94%), and the band gap decreased to 3.08 and 3.06 eV with the incorporation of Al and Cu into ZnO thin films, respectively. The electrical conductivity also improved by Al and Cu doping of ZnO TFs.

Structural, surface morphological, optical and thermoelectric properties of sol–gel spin coated Zn doped CdS thin films

The present work is focussed on Zinc (2, 4, 6, 8 and 10 wt%) doped CdS thin films synthesized by sol–gel spin coating method and deposited on glass substrates. X-ray diffraction patterns of Zn doped CdS thin films exhibit cubic structure. The microstructural properties such as crystallite size, lattice constant, microstrain, dislocation density and stacking fault probability in the films were reported. The surface morphology and topography of the films was studied by using field emission scanning electron microscopy and atomic force microscopy. The incorporation of Zn in CdS and elemental composition of the films has been confirmed with X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS). Raman spectrum of Zn doped CdS thin films exhibits 1LO and 2LO phonon modes. The optical band gap of CdS thin films increased from 2.63 to 2.73 eV with the increase of Zn dopant from 2 to 10%. Thermoelectric power measurements show negative Seebeck coefficient indicating n-type semiconducting behaviour. The carrier concentration of Zn doped CdS thin films at room temperature are found to be in the range of 1019–1020 cm−3 suggesting that the prepared films are degenerate semiconductors. The increase in thermal conductivity of Zn doped CdS thin film is due to the increase in carrier concentration of the films. The lattice thermal conductivity of Zn doped CdS thin films had an inverse temperature dependent and at high temperatures shows the dominance of phonon scattering.

СИНТЕЗ ТА АНТИМІКРОБНА АКТИВНІСТЬ НАНОЧАСТИНОК СРІБЛА СТАБІЛІЗОВАНИХ ЦИТРАТ-АНІОНАМИ

Widespread use of synthetic antimicrobial drugs leads to the development of antibiotic resistance of pathogenic strains of microorganisms. Therefore, today researchers are very interested in drugs based on nanoparticles of metals, in particular silver and copper, which have antibacterial, antifungal and antiviral activity. One of the reasons for the high interest of researchers in AgNPs as an antimicrobial agent is the significantly lower toxicity of AgNPs compared to Ag+ ions. High antibacterial efficiency of silver nano¬particles is achieved due to their developed surface, which provides maximum contact with the environment. In addition, such nanoparticles are quite small and are able to penetrate cell membranes, to affect intracellular processes from within. Therefore, the aim of this work was to obtain concentrated colloidal silver solutions stabilized by citrate anions, which simultaneously provide satisfactory stabilization of colloidal silver solutions and are non-toxic, as well as to investigate the antimicrobial action of synthesized AgNPs. The solution of citrate stabilized silver nanoparticles (AgNPs) have been obtained via the reaction of reduction of silver nitrate by hydrazine in alkaline medium in the presence of sodium citrate. AgNPs were investigated using transmission electron microscopy (TEM) and UV-vis spectroscopy and the particles size and particles size distribution (PSD) were determined. It was observed that obtained AgNPs are mainly spherical shape. It was found that the mean diameter and PSD of AgNPs determined using TEM and UV-vis spectroscopy are close and equal to 14 and 5 nm and 15 and 4 nm respectively. Obtained solution was concentrated by evaporation at 70 C under reduced pressure up to achievement of AgNPs concentration equal to 200 mg/L. On the base of comparison of optical properties of initial silver sol and concentrated solution the minority of agglomeration of AgNPs was statement. At the same time AgNO3 test showed no change of UV-vis spectrum of concentrate that points on the absence of reducing agent in the solution; this fact indicate that hydrazine was eliminated from during the evaporation of initial AgNPs solution and obtained concentrate did not consist the toxic impurities. Antimicrobial activity of obtained citrate stabilised AgNPs against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacterium was tested using disk diffusion method. It was found that AgNPs shown significant bactericidal effect even at low (25 mg/L) concentration as well as some higher efficiency against Gram-negative bacterium. There was also a slightly higher antimicrobial activity of the drug against gram-negative bacteria Escherichia coli compared with gram-positive bacteria Bacillus subtilis, due to the different structure of cell walls. In particular, the walls of gram-positive bacteria consist mainly of peptidoglycan (murein), and gram-negative bacteria have cell walls with a layer of peptidoglycan and an outer membrane with a lipopolysaccharide component, which is not present in gram-positive bacteria. Based on the studies, it can be concluded that the proposed method of synthesis of AgNPs is suitable for obtaining highly concentrated silver sols. This method of synthesis is simple in hardware design, scalable, and the resulting colloidal solutions are stable and do not contain harmful impurities. Therefore, due to the high antibacterial activity of citrate-anion-stabilized AgNPs against certain types of gram-positive and gram-negative bacteria, it can be recommended for the manufacture of bactericidal drugs for biomedical purposes.

The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

This study investigated polysiloxane hybrid sol-gel coatings synthesized from tetraethyl orthosilicate (TEOS), 3-(trimethoxysilyl)propyl methacrylate (MAPTMS) and two different precursors, i.e., methyl- or ethyl- methacrylate (MMA or EMA), as corrosion protection of aluminium alloy 7075-T6. The hypothesis was that the additional alkyl group might affect the chemical properties and, consequently, the corrosion properties. Synthesis of the sols proceeded in two steps, each involving either MMA or EMA in the same molar ratio. The resulting sols, siloxane-(poly(methyl methacrylate-co-MAPTMS)) or siloxane-(poly(ethyl methacrylate-co-MAPTMS)), were applied on aluminium alloy followed by characterization in terms of chemical structure and composition, topography, wettability, adhesion and corrosion resistance in 0.1 M sodium chloride solution. The chemical properties of sols, monoliths and coatings were investigated using Fourier transform infrared spectrometry, solid state nuclear magnetic resonance spectrometry, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. Coatings were similar in terms of surface topography, while the wettability of the coating with EMA showed 6° greater water contact angle compared to the coating with MMA. Both coatings were shown, by electrochemical impedance spectroscopy in 0.1 M NaCl solution, to act as barriers to protect the underlying substrate in which coating with EMA exhibits better protection properties after 2 months of immersion. Adhesion tests confirmed the highest grade of adhesion to the substrate for both coatings. Testing in a salt-spray chamber demonstrated excellent corrosion protection, where coatings remaining intact after more than 600 h of exposure.

Antibacterial Properties of Sol–Gel Biomaterials with Different Percentages of PEG or PCL

AbstractThe aim of this work is the synthesis of antibacterial biomedical implants using sol–gel method. Different percentages (6, 12, 24, 50 wt%) of polyethylene glycol (PEG) or poly(ε‐caprolactone) (PCL) are embedded in the silica matrix; subsequently, high amounts of chlorogenic acid (CGA 20 wt%) are added to SiO2/PEG and SiO2/PCL sol. Fourier transform infrared spectroscopy is used to evaluate the interactions among different organic and inorganic phases in the hybrid materials. Furthermore, in order to study the potential antibacterial properties of the materials, two different bacterial strains are used and the diameter of zone of inhibition is observed. CGA is a natural product that is present in coffee beans, as well as tea leaves, grapes, and apples. This natural molecule is added to sol–gel materials due to its many health‐promoting properties.

Controllable doping and passivation of ZnO thin films by surface chemistry modification to design low-cost and high-performance thin film transistors

Solution-processed metal oxide thin-film transistors have become more popular as they can be used to fabricate transparent and flexible electronics at low cost. However, additional and complex processes for trap-site passivation and doping hinder the potential of the low-cost solution process. This study introduces a surface passivation process involving treatment with 3-aminopropyltriethoxysilane (APTES) that can enhance the electrical properties of ZnO sol–gel thin films. Optical, chemical, and structural analyses of ZnO sol–gel thin films revealed that their trap sites were passivated successfully through APTES treatment under basic conditions. Taking advantage of this process, high-mobility and negligible-hysteresis ZnO thin-film transistors were successfully fabricated, showing an Ion/Ioff of 105, hysteresis as low as 1.13 V, and mobility of up to 0.117 cm2/Vs. Furthermore, a characteristic transition of ZnO sol–gel thin films from semiconductive to semimetallic was observed during investigations with various APTES concentrations.

Improved mechanical and anticorrosion properties of metal oxide-loaded hybrid sol–gel coatings for mild steel in a saline medium

A hybrid organic–inorganic sol–gel coating was successfully prepared and subsequently functionalized individually with five different metal oxide additives. The effect of the incorporated oxides on the corrosion protection performance and scratch-resistance properties of the hybrid base coating on mild steel substrates was investigated using electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) as well as mechanical testing. The steel-coated specimens were immersed in 3.5 wt.% NaCl corrosive medium for two weeks and the results reveal an excellent corrosion protection performance by all coating formulations with a significant high corrosion-resistance property for the sample loaded with molybdenum oxide. Scanning electron microscopy (SEM) images proved the absence of corrosion signs, defects, micro cracks, or delamination on the surface of the coated samples. Compared with the pure hybrid coating, all the metal oxide-embedded coatings (except for the sample loaded with yttrium(III) oxide) show comparable aqueous contact angle values as well as enhanced hardness and adherence properties. No noticeable dependence was observed for the surface roughness parameters as a function of the type of incorporated metal oxide within the sol–gel matrix. Overall, the results of this study demonstrate that metal oxides can be advantageous to the desired properties of hybrid sol–gel coatings applied to steel surfaces.

Properties of alumina sol prepared via inorganic route

In this research, alumina sol has been synthesized via an inorganic route using inexpensive starting materials including aluminum nitride, deionized water, ammonia, and nitric acid. A clear, homogenous and stable sol was achieved which converted to a soft gel at 60 °C. The physical and microstructural properties of synthesized sol such as pH, particle size, density, solid content, phase analysis, nature of bounds, and thermal behavior were investigated. The pH of the prepared sol was in the range of 3–4, and the solid content was measured by about 6% at the temperature of 1000 °C. Utilizing the SEM micrographs, the average particle size of the dried and calcined sol at 110 °C and 1000 °C were measured less than 20 nm and 40 nm, respectively. XRD patterns of calcined sol at 200, 600, 1200, and 1400 °C revealed the formation of β-alumina (boehmite), γ-alumina, and α-alumina, respectively. Above the temperature of 1200 °C clear and sharp peaks of α-alumina appeared. Also, TG-DSC patterns confirmed the formation of β phase at 200 °C, boehmite into γ transformation at approximately 450 °C, and the alter of γ into α phase at temperatures above 1000 °C.

Mechanical properties and decohesion of sol–gel coatings on metallic and glass substrates

The sol–gel coating method is considered to be simple and easy to implement to lead to organic/inorganic hybrid coatings. In addition, the application of thin films by this technique is inexpensive and applicable on large substrates without form restriction. In this context, thin sol–gel coatings based on a mixture of three alkoxysilanes and synthesized in purely aqueous phase with different thicknesses and with the presence or not of ZrO2 nanoparticles, were applied on metallic and glass substrates. After application and curing, the mechanical properties of sol–gel coatings were characterized by Berkovich nanoindentation with continuous stiffness measurement mode (CSM). The effective elastic moduli as well as the hardness values were estimated for each coating along the indentation depth and as a function of the substrate material and sol–gel characteristics. The effect of a annealing at higher temperature was also studied. Then, the failure modes of sol–gel coatings were investigated using both Berkovich nanoindentation and nanoscratch technique with a 5 µm radius spherical diamond tip. Careful microscopic observations of residual imprints and residual grooves both exhibit chipping in case of thick coating especially on glass substrate and no dramatic failure for thin coating applied on both substrates. It is shown in this work that the mechanical properties of the sol–gel and the mechanical stability of coatings on substrates are influenced dramatically by the presence of nanoparticles and the thermal treatment. Finally, interfacial fracture toughness of sol–gel coatings on substrate was estimated using analytical model from the literature and Ashby map based on experimental results was created using performance indices in order to proceed to sol–gel coating selection.

Effect of Solution Conditions on the Properties of Sol-Gel Derived Potassium Sodium Niobate Thin Films on Platinized Sapphire Substrates.

If piezoelectric micro-devices based on K0.5Na0.5NbO3 (KNN) thin films are to achieve commercialization, it is critical to optimize the films’ performance using low-cost scalable processing conditions. Here, sol–gel derived KNN thin films are deposited using 0.2 and 0.4 M precursor solutions with 5% solely potassium excess and 20% alkali (both potassium and sodium) excess on platinized sapphire substrates with reduced thermal expansion mismatch in relation to KNN. Being then rapid thermal annealed at 750 °C for 5 min, the films revealed an identical thickness of ~340 nm but different properties. An average grain size of ~100 nm and nearly stoichiometric KNN films are obtained when using 5% potassium excess solution, while 20% alkali excess solutions give the grain size of 500–600 nm and (Na + K)/Nb ratio of 1.07–1.08 in the prepared films. Moreover, the 5% potassium excess solution films have a perovskite structure without clear preferential orientation, whereas a (100) texture appears for 20% alkali excess solutions, being particularly strong for the 0.4 M solution concentration. As a result of the grain size and (100) texturing competition, the highest room-temperature dielectric permittivity and lowest dissipation factor measured in the parallel-plate-capacitor geometry were obtained for KNN films using 0.2 M precursor solutions with 20% alkali excess. These films were also shown to possess more quadratic-like and less coercive local piezoelectric loops, compared to those from 5% potassium excess solution. Furthermore, KNN films with large (100)-textured grains prepared from 0.4 M precursor solution with 20% alkali excess were found to possess superior local piezoresponse attributed to multiscale domain microstructures.

Interfacial Energy Level Tuning for Efficient and Thermostable CsPbI2Br Perovskite Solar Cells.

Inorganic mixed‐halide CsPbX3‐based perovskite solar cells (PeSCs) are emerging as one of the most promising types of PeSCs on account of their thermostability compared to organic–inorganic hybrid counterparts. However, dissatisfactory device performance and high processing temperature impede their development for viable applications. Herein, a facile route is presented for tuning the energy levels and electrical properties of sol–gel‐derived ZnO electron transport material (ETM) via the doping of a classical alkali metal carbonate Cs2CO3. Compared to bare ZnO, Cs2CO3‐doped ZnO possesses more favorable interface energetics in contact with the CsPbI2Br perovskite layer, which can reduce the ohmic loss to a negligible level. The optimized PeSCs achieve an improved open‐circuit voltage of 1.28 V, together with an increase in fill factor and short‐circuit current. The optimized power conversion efficiencies of 16.42% and 14.82% are realized on rigid glass substrate and flexible plastic substrate, respectively. A high thermostability can be simultaneously obtained via defect passivation at the Cs2CO3‐doped ZnO/CsPbI2Br interface, and 81% of the initial efficiency is retained after aging for 200 h at 85 °C.

Defects characterisation and studies of structural properties of sol–gel synthesised MgFe2O4 nanocrystals through positron annihilation and supportive spectroscopic methods

ABSTRACTMagnesium ferrite (MgFe2O4) nanocrystalline samples were prepared by sol–gel method and by sintering at temperatures from 300°C to 1000°C. X-ray diffraction and electron microscopic studies showed an increase in crystallite sizes and a decrease in lattice constants at higher sintering temperatures. UV-Vis absorption measurements depicted blue shift for samples of smaller crystallite sizes (dc) with a resultant increase of the band gap energies (Eg. = 2.07 eV at dc = 49 nm to 3.10 eV at dc = 6 nm, for samples sintered at 1000°C and 300°C, respectively). Fourier transform infrared spectroscopy of the samples proved the formation of the spinel structure while energy dispersive X-ray analysis pointed out the non-stoichiometric composition, which implied the presence of vacancy type defects that could modify the structural and magnetic characteristics of the compounds. This necessitated the use of positron annihilation lifetime and coincidence Doppler broadening spectroscopic studies for defect characterisation and the results indicated distinct redistribution of cations within the unit cells, making the compound overwhelmingly turn towards a normal spinel configuration at smaller nanocrystalline sizes. Positrons were trapped in larger vacancies of increasing numbers in smaller crystallites. The vacancies turned out to be formed at the octahedral sites where the increased ionic radius of Fe3+ became large enough to reduce the occupancy significantly. Mossbauer spectra analysis indicated an increase of the ferromagnetic properties in samples sintered at higher temperatures. At 300°C and 400°C, the samples dominantly showed paramagnetic behaviour.

Preparation and properties of CeO2 sols stabilized by polyvinyl alcohol

Preparation and properties of CeO2 sols stabilized by polyvinyl alcohol

Piezoelectric properties of sol–gel-derived (K0.16Na0.84)0.5Bi4.5Ti4O15 ceramics improved by a deft process optimization

Two types of (K0.16Na0.84)0.5Bi4.5Ti4O15 + 0.5ω%CeO2 (KNBT-Ce0.5) ceramics were synthesized by using the conventional sol–gel method and an optimized process, respectively. Phase structure and morphology of KNBT-Ce0.5 ceramics were characterized by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The density and piezoelectric performance of ball-milled KNBT-Ce0.5 ceramics were significantly improved compared with that of the conventional sol–gel method-derived KNBT-Ce0.5 ceramics. The maximum of piezoelectric coefficient (d33) was found to be 27 pC/N for the ball-milled KNBT-Ce0.5 ceramics, which were calcined at 650 °C, together with the high Curie temperature (~648 °C) and the high resistivity (higher than 106 Ω cm−1). In addition, the good temperature stability of piezoelectric performances was exhibited for the KNBT-Ce0.5 ceramics, which was synthesized by the optimal process.

Influence of Pd-doping on structural, morphological, optical and electrical properties of sol–gel derived CuO thin films

CuO and Pd:CuO thin films have been deposited by the sol–gel and spin coating technique. The films thickness was controlled by the number of successive layers on the substrates. Subsequently, the physical properties of the films were studied as a function of their thickness. XRD spectra have shown that films consisting of four layers revealed the best crystallinity. Optical transmission as well as energy gap values decreased with thickness, while the resistivity was increasing. Palladium at five different concentrations was introduced into 4-layered (228 nm). Raman measurements of all doped films confirmed the structure of CuO. AFM studies revealed the pyramidal nano-textured surface as the Pd concentration changed. A clear correlation between the broadening of the optical band gap with increasing Pd doping concentration was observed. The electrical resistivity varied from 1.2 to 1.6 × 102 Ω cm.

Effect of Indium Doping on Optical Parameter Properties of Sol–Gel-Derived ZnO Thin Films

Abstract Zinc oxide (ZnO) has gained great interest for two decades, and its structural, optical, and electrical properties have been investigated by scientists for technological applications. The optical properties of ZnO provide an opportunity for its application in solar cells, lasers, and light-emitting diodes. We prepared ZnO thin films with various In doping levels by using a spin coating technique, and characterised their morphological and detailed optical properties for optical applications. According to the morphological properties obtained by atomic force microscopy, the film surfaces are homogeneous and the In doping level affects the surface morphology of the films. The optical properties of the films were investigated using an ultraviolet–visible spectrometer, and some optical parameters such as band gap, refractive index, extinction coefficient, single oscillator parameters, real and imaginary functions of the dielectric coefficient, and optical conductivity were calculated and discussed in detail. The various In doping levels affected the optical properties, and the In-doped ZnO thin films can find applications in industry.