Band Gap Of Films Research Articles

Mathematical modelling based on deposition parameters for optical band gap estimation of Sb2S3 thin films

A mathematical prediction model was developed to predict the band gap of Sb2S3 films based on the synthesis parameters. For the optimization of process parameters, a chemometric optimization approach was used instead of the traditional method. The band gaps of chalcogenide films were measured between 1.68 eV and 1.98 eV. The developed model was able to predict the band gap of the optimized Sb2S3 sample, measured as 1.71 eV, as 1.77 eV. The mathematical model achieved the band gap prediction of both the optimized Sb2S3 film and the test sample with a relative error of 3.51% and 2.23%, respectively. The data revealed that the developed model could reliably predict the band gap of Sb2S3 nanoparticles with a relative error of less than 5%. These findings may provide a significant advantage in nanoscale applications in terms of better understanding the predictability of the band gap of Sb2S3 films prior to synthesis.

Structural and optical properties of Cu implanted Ge thin films

Effects of rapid thermal annealing (RTA) on 100 keV Cu implanted germanium (Ge) thin films were studied in the present report. The Cu ion implantation into Ge films was carried out at different ion fluences 5 × 1015 and 1 × 1016 ions/cm2. Subsequently, the implanted samples were subjected to RTA at 600 °C. XRD and Raman results illustrate the amorphization of implanted films, whereas RTA results in crystallization. Crystallite size increases from 10.5 to 11.6 nm with fluence for RTA-treated samples. The bandgap of pristine film is 0.73 eV, which gets narrowed to 0.59 eV with an increase in ion fluence. RTA leads to increase in band gap up to 1.16 eV due to recovery of lattice damage and recrystallization of films. XPS analysis of RTA-treated implanted films reveals the presence of Ge, Ge suboxides, and Cu. The broad PL emission in the visible region signifies the possible use of Ge for optoelectronic applications.

Study on the effect of sputtering pressure on the physical properties of InN films on ITO substrate and the dependence of carrier transport characteristics of Li-doped p-NiO/n-InN heterojunction on the environmental temperature

The exceptional performance of ITO substrate has made it possible to use indium nitride (InN) material in a variety of applications. The combination of lithium-doped NiO and n-type InN in a heterojunction shows great potential as a material for optoelectronic devices. This study investigates the influence of sputtering pressure on the crystal structure, surface morphology, optical properties, and electrical characteristics of InN thin films prepared on ITO substrates through magnetron sputtering. The research findings indicate that the InN films grow preferentially along the (002) crystal plane, with the best crystalline quality observed under a sputtering pressure of 1.5 Pa. Subsequently, the changes in the optical bandgap, transmittance, and reflectance of the InN films with varying sputtering pressure were discussed. The study also discusses a comprehensive analysis of the trends in the electrical characteristics of the InN films with sputtering pressure and environmental temperature, demonstrating their excellent thermal stability at high temperatures. Additionally, Li-doped p-NiO/n-InN heterojunction devices were fabricated and analyzed to determine the influence of environmental temperature on the carrier transport characteristics of the devices, revealing their favorable electrical properties at different temperatures. This research enriches the field of InN material studies and opens up new prospects for the performance and practical applications of InN optoelectronic devices.

Effects of Oxygen Partial Pressure on the Electronic Properties and Chemical State of MgO/SiO<sub>2</sub>/Si(100) Thin Films

Magnesium Oxide (MgO) thin films were deposited on SiO2/Si substrate by electron beam evaporation. The properties of MgO thin film with and without oxygen partial pressure have been investigated by X-ray photoelectron spectroscopy (XPS), Reflection Electron Energy Loss Spectroscopy (REELS), and Ultra-Violet Photoemission Spectroscopy (UPS). The XPS was used to investigate the chemical state of the film. REELS spectra revealed that MgO thin films deposited under oxygen partial pressure had band gaps of 6.07 eV. Meanwhile, the band gap for MgO thin films grown without oxygen partial pressure was 7.17 eV. The UPS results showed that the work functions of MgO thin film with and without oxygen partial pressure are 4.75 and 4.84 eV, respectively. In the MgO thin film with oxygen partial pressure, the intensity for the valence band peak at 12.16 eV decreased, but the work function remained relatively the same. Our results demonstrated that the oxygen partial pressure played a crucial role in improving the electronic properties of MgO thin films.

Comparative study of Cu2XSnS4 (X = Ni, Co, Mn or Fe) films synthesized by spray pyrolysis under air atmosphere, as suitable absorber layers for photovoltaic applications

The present work deals with the synthesis of an absorber Cu2XSnS4 sulfide (X = Ni, Fe, Co or Mn) thin films by a spray pyrolysis method on hot substrate and under air atmosphere for low cost solar cell. Chemical composition analyzes by energy-dispersive X-ray spectroscopy (EDS) revealed the presence of all the chemical elements (Cu, Sn, S and Co, Ni, Mn or Fe) with a composition close to the stoichiometry of the layers of Cu2NiSnS4 (CNTS), Cu2CoSnS4 (CCTS) and far from the stoichiometry for the layers of Cu2MnSnS4 (CMTS) and Cu2FeSnS4 (CFTS). The X-ray diffraction (XRD) analyzes showed the crystallization of the desired phase such as the cubic phase of CNTS with a preferential orientation (111) and the stannite phase of CCTS and CMTS with a preferential orientation (112), except for the CFTS film which is poorly crystallized. SEM analyzes show that CNTS, CCTS and CMTS layers exhibit a rather homogeneous and compact surface with nodule distribution. The CFTS layer surface shows excrescences separated by voids leading to a porous and diffusing surface. The optical analyzes indicated a high absorption coefficient of the order of 104 cm−1 in the visible range for all the layers and an optical band gap of 1.62, 1.58 and 1.64 eV for the layers CNTS, CCTS and CMTS respectively, whereas the direct band gap of CFTS film is higher (∼ 2.23 eV). The comparison of CXTS films synthesized in the same conditions demonstrates that the CNTS and CCTS films have the most suitable features (optical, electrical, mechanical and oxidation resistance) to be used as absorbing layer in low cost solar cell.

Effect of nitrogen flow ratio on the structure and optical properties of AlN film

Aluminum nitride (AlN) films with different optical properties were prepared by radio frequency (RF) reactive magnetron sputtering technique under different nitrogen (N2) flow ratios. The films' microstructure and optical properties were investigated by XRD, XPS, SEM, UV-VIS and PL. The results showed that all the prepared films had hexagonal wurtzite structure and the sample prepared at 35 % N2 flow ratio obtained higher crystal quality and larger grain size (39 nm). The selective orientation of the films changed from (100) to (002) with the N2 flow ratio, accompanied with a surface morphology changed from worm-like to mixed structure, and eventually to a very regular pebble shape with a compact arrangement. The average transmission of the films exceeded 83 % in the wavelength range of 300–800 nm. The major internal defect affecting the band gap of AlN films was nitrogen-vacancy (VN), and the growth orientation and internal defects of AlN films were controlled by the N2 flow ratio to achieve the regulation of the energy band gap in a small range (5.47–5.68 eV). This can meet the requirement of solar-blind ultraviolet (<280 nm) photoelectric detection.

PEALD deposited aluminum hafnium mixed oxide dielectrics for amorphous-IGZO TFTs

(Al–Hf) mixed oxide thin films (HfAlO) are attracted by many researchers because of their outstanding optical and electrical properties compared to hafnium oxide (HfO2). This study prepared HfAlO films at 300 °C using plasma-enhanced atomic layer deposition (PEALD). Changing the cycle ratio of HfO2 and aluminum oxide (Al2O3), the mixing effect on the properties of HfAlO film was studied. The characterization of the HfAlO films was investigated using spectroscopic ellipsometry (SE), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray reflectivity (XRR), scanning electron microscopy (SEM), and UV–vis spectroscopy. The results show that the aluminum content and optical bandgap of the HfAlO films increased with the increase of the Al2O3 cycle ratio. The dielectric constant of the HfAlO film with a 20 % Al2O3 cycle ratio (cycles of Al2O3/(cycles of Al2O3 + cycles of HfO2)) reaches ∼ 26, and the breakdown electric field is about 6.5 MV/cm. Pure HfO2 and 20 % Al2O3 cycle ratio deposited HfAlO was used as the gate dielectric layer, and the influence on the performance of amorphous indium gallium zinc oxide (a-IGZO) thin film transistor (TFT) was studied. A-IGZO TFT with a 20 % Al2O3 cycle ratio mixed HfAlO film as the gate dielectric exhibits the best performance, showing a high Ion/Ioff ratio of 1.3 × 109, a saturation mobility of ∼5.8 cm2/Vs, a subthreshold slope of 88 mV per decade and a low threshold voltage of −0.1V.

Enhanced conductivity behavior of titanium-based bipolar plate oxide films through microalloying: First-principles calculations and experimental investigations

Presently, the formation of oxide films on the surface of Ti-based bipolar plates results in decreased electrical conductivity. This limitation frequently curtails the operational lifespan of proton exchange membrane fuel cells (PEMFCs). In this study, we engineered Ti alloy bipolar plate materials using an elemental screening process and validated their performance through experimentation. The elemental screening results identified eight elements, specifically Ni, Cr, Mo, Ta, W, Fe, Co, and Zn, as promising candidates for bipolar plate materials. Among these, Mo exhibited a pronounced affinity for incorporation into the TiO2 oxide film. Conductivity measurements of passivated bipolar plates indicated that the Ti–Mo alloy displayed excellent electrical conductivity (1.699 × 1020 Ω m−1). Notably, the introduction of Mo (with an energy level of 1.64 eV) significantly reduced the band gap of the oxide film. Importantly, even after continuous potential oxidation for 10,000 s, the interfacial contact resistance (ICR) of Ti-0.35Mo (9.80 mΩ cm2) remained below the threshold set by the American DOE standard (ICR <10 mΩ cm2). Consequently, this research successfully devised a bipolar plate material utilizing a Ti–Mo alloy and proposed an innovative strategy for improving the conductivity of oxide films in bipolar plate materials via an elemental screening approach.

Tunable room-temperature ferromagnetism in RF magnetron sputtered Al2Cr2Cu2O8 thin film

Metal oxide solid solution thin films containing ternary mixtures of Alumina (Al2O3), Chromia (Cr2O3) and Cupric oxide (CuO) were successfully prepared combinatorially on FTO, quartz glass and Si substrates using radio frequency (RF) magnetron sputtering (vertical geometry; on-axis sputtering) technique with RF powers of 200 W and 100 W. XRD analysis prove the development of tetragonal phase Al2Cr2Cu2O8 in sputtering target. Al2Cr2Cu2O8 film deposited on Si wafer and quartz glass exhibits amorphous nature, whereas, the film deposited on FTO substrates exhibit crystalline structure with tetragonal phase owing to polycrystalline nature of the FTO substrates. Formation of high compositional purity with acceptable stoichiometric ratio of ternary metal oxide mixtures of Al2Cr2Cu2O8 was ascertained from the EDX spectra. The thicknesses of Al2Cr2Cu2O8 thin films are found to be in the ranges from 259 to 314 nm. Optical study showed that the optical energy band gap of Al2Cr2Cu2O8 thin film deposited on quartz substrates increased to 3.84 eV from 3.78 eV with decreasing RF power from 200 W to 100 W. The spin orbital splitting (SOS) between Cr 2p1/2 - Cr 2p3/2 and Cu 2p1/2 - Cu 2p3/2 were measured to be 9.9 eV and 19.3 eV by XPS for 200 W sputtered Al2Cr2Cu2O8 film on quartz substrate, which are the characteristics of Cr3+ and Cu2+ oxidation states, respectively. In addition, XPS analysis also confirms the presence of various oxygen vacancies in Al2Cr2Cu2O8 thin films (as-deposited and 1000 °C annealed films) on quartz substrate with RF power of 200 W, which is the most favorable condition for the presence of room temperature ferromagnetic properties observed in the present study.

Discovery of a Robust P‐Type Ultrawide Bandgap Oxide Semiconductor: LiGa5O8

AbstractLiGa5O8, an ultrawide bandgap semiconductor, is discovered to exhibit p‐type conductivity at room temperature, making it the widest bandgap p‐type oxide semiconductor known to date. Utilizing a mist–chemical vapor deposition (M–CVD) technique, successful growth of p‐type LiGa5O8 thin films on c‐plane sapphire and GaN‐on‐sapphire substrates is achieved. Characterization through X‐ray diffraction and cross‐sectional scanning transmission electron microscopy (STEM) confirms the spinel cubic crystal structure of LiGa5O8. Comprehensive investigations into the effects of growth conditions on surface morphology, material composition, and p‐type charge carrier transport are conducted. As‐grown LiGa5O8 thin films exhibit a broad range of hole concentrations, ranging from 1015 cm−3 to 1018 cm−3, depending on growth conditions. Elemental compositions of Li, Ga, and O are extracted using X‐ray photoemission spectroscopy (XPS). Both Li‐poor and Li‐rich LiGa5O8 films demonstrate p‐type conductivity. Optical absorption measurements reveal the bandgap of LiGa5O8 films to be ≈5.36 eV. Additionally, temperature‐dependent Hall measurements of the p‐type LiGa5O8 thin films show robust p‐conductivity down to 150 K. Results from this study promise the advancement of future power electronics based on ultrawide bandgap Ga2O3 and related semiconductor material systems.

Swift heavy ion irradiation induced modifications on the structure, optical and electrical properties of pulsed laser deposited anatase TiO2 thin films

The swift heavy ions of Ag7+ (100 MeV) were used to irradiate the anatase TiO2 thin films prepared by pulsed laser deposition (PLD) technique on quartz substrates. The effect of ion fluences (1×1012, 1×1013 and 1×1014 ions/cm2) on the structure, surface morphology, optical and electrical properties are investigated through several analytical techniques such as XRD, Micro-Raman, FTIR, XPS, AFM, FESEM, UV–visible and Hall measurements. The analysis of XRD data shows a gradual shift in the (101) plane toward higher diffraction angle on increasing the ion fluence which increases the lattice strain in the films. The EDS spectra reveal a modest Ti-rich composition with a significant shift following irradiation for both as-grown and irradiated films. The development of hillocks at increased ion fluence and considerable grain splitting following irradiation are observed in SEM micrographs. AFM images exhibit increase in surface roughness with the increase in ion fluence. Moreover, there is a significant drop in the band gap of the irradiated thin films from 3.92 to 3.44 eV with the increase in ion fluence. The various electrical parameters such as carrier concentrations (n), Hall mobility (μ), electrical resistivity (ρ), Hall coefficient (RH), etc., are determined by the Hall measurements at room temperature. This study indicates that the SHI irradiation plays a significant role in tunning the physical properties of anatase TiO2 thin films.

Epitaxial growth and characterization of magnesium gallate (MgGa2O4) thin films by pulsed laser deposition

In this work, crystalline MgGa2O4 thin films were grown on c-plane sapphire substrates using the pulsed laser deposition (PLD) technique in a broad range of temperatures and oxygen pressures. The parameters for the crystalline growth were within the temperature range of 300 ℃ to 700 ℃ and the pressure range of 1 × 10-1 to 1 × 10-3 Torr. The acquired XRD patterns confirmed the film growth along the [111] preferential crystal orientation in the lattice and the rocking curve measurement of the prominent (222) plane showed an increasing trend of the crystallinity with growth temperature and pressure. Furthermore, the XRD phi (φ) scan demonstrated the six-fold rotational symmetry of the MgGa2O4 films and the epitaxial relationship of 30° between the film and sapphire substrate. The XPS spectra confirmed the presence of +2 and +3 oxidation state for Mg and Ga respectively, in the films and vacancies that increase with decreasing oxygen partial pressure. The direct bandgap of MgGa2O4 films was obtained to be ∼5.27 ± 0.03 eV by analyzing the UV-Vis absorbance spectra. The film surface exhibited a granular morphology with an increasing trend in grain size as the temperature increased. The refractive index and thickness of these films were in the range of ∼1.90 ± 0.02 and ∼70 ± 2.0 nm, respectively determined from the fitted spectroscopic ellipsometry data. The surface roughness was obtained from AFM images and found to be in good agreement with those obtained from the analysis of the ellipsometry data.

Investigation on the Mist Intensity to Deposit Gallium Oxide Thin Films by Mist Chemical Vapor Deposition

In this study, a novel, simple, and robust mist chemical vapor deposition is demonstrated, compatible with existing industrial practices to deposit gallium oxide thin films and influence of mist intensity on the properties of gallium oxide. The intensity of the mist generation is optimized to obtain smooth and uniform thin films. The thin film deposited in this work is mixed phase polycrystalline gallium oxide. Ultraviolet–visible–near‐infrared spectroscopy and photo response of thin film unveil that gallium oxide thin film is responsive to ultraviolet wavelengths including deep ultraviolet‐C and ultraviolet‐B bands and the mist‐generation intensity has negligible influence on the bandgap of the thin film. Thickness of thin film can be altered by varying the mist intensity. It is observed that there is no appreciable impact on refractive index of varying mist intensity. Morphological studies prove the formation of ultrasmooth thin film with root mean square value of 0.628 nm; which is closer and/or better than conventional semiconductor thin‐film deposition processes used for depositing Ga2O3.

Investigation on visible spectral response of spray coated Ni doped CuGaS2 thin films for photodetector application

The visible light spectrum attracts vast interest in photodetector applications and takes an integral part in image sensing and communication. Ternary chalcopyrite, such as CuGaS2 can be used for visible light detection owing to its higher light absorption coefficient and wider bandgap. This work presents pristine and Nickel-doped CuGaS2 (0.5, 1.0, 1.5 wt. %) thin film photodetectors prepared by the low-cost Chemical Spray Pyrolysis technique. Structural analysis confirms the formation of the pure CuGaS2 phase and the evidence of Ni inclusion inside the lattice. The optical bandgap of the Ni-doped CGS thin films was reduced compared with pristine CuGaS2, leading to higher absorption in the visible region. The interaction of photons with CuGaS2 and its photoconductive mechanism is probed through photoresponse studies. The responsivity and detectivity were calculated for all the photodetectors under constant bias (1V) and power density (4 mW/cm2). All the devices show excellent photoresponse despite having a higher photosensitive area of 1 cm2 and a very low bias for operation. Particularly, 0.5 wt. % Ni-doped CGS photodetector device showed higher responsivity and detectivity of 1.6 μAW−1 and 19.6 × 106 Jones respectively than others. The admirable optical and electrical properties due to Ni doping played a crucial role in this superior performance. Hence, our investigation suggests Ni-doped CuGaS2 thin films can be employed in the fabrication of thin film photodetector devices.

Bandgap modulation and phase boundary region of multiferroic Gd, Co co-doped BiFeO3 thin film

Ferroelectric polarization is a crucial factor to induce photovoltaic effect in ferroelectric materials. Here, a novel modulation of bandgap by Gd and Co co-doped BFO is found for a polycrystalline Bi0.9Gd0.1Fe0.85Co0.15O3 thin film prepared by the sol–gel process. The ferroelectric properties, magnetic properties, and bandgap of the BFO films were altered by doping Gd and Co. This work has led to a greater understanding of bismuth ferrate, and it proposes the Bi0.9Gd0.1Fe0.85Co0.15O3 thin film for the possibility of better preparation of high conversion efficiency ferroelectric photovoltaic devices.

Tuning the physiochemical properties of polycaprolactone-hydroxyapatite composite films by gamma irradiation for biomedical applications

Physiochemical properties of polycaprolactone-hydroxyapatite (PCL-HAp) composites were investigated in the pristine and after irradiation of γ rays (25, 50, 75, and 100 kGy). PCL-HAp composites were synthesized by solvent evaporation and characterized using spectroscopic methods as well as biological assays. The surface roughness (RMS) of the irradiated composite film (at 75 kGy) was 80 times higher than that of the pristine. Irradiation tailors the contact angle of the films from 77° to 90° (at 100 kGy). A decrease in particle size (at 100 kGy) of HAp nanorods in PCL-HAp composites film was observed. The XRD peak of PCL was slightly shifted from 21.2° to 21.7° (at 100 kGy) with the decrease in crystallite size. The peak intensity of the PCL and HAp altered on irradiation that was confirmed by FTIR and Raman analysis. Further, the bandgap of the irradiated film was lowered by 13 % (at 25 kGy). The luminescence intensity decreased due to the non-radiative process induced by the irradiation defects. All the samples possess hemocompatibility percentage of <10 % as per ASTM standards. At 75 kGy, fibroblast cell proliferation was higher than the pristine and other doses. The gamma-irradiated PCL-HAp composite films are potential candidates for tissue engineering applications.

Hybridization of ellipsometry and XPS energy loss: Robust band gap and broadband optical constants determination of SiGe, HfON and MoOx thin films

In this study, we compare the robustness of optical constants and optical band gap determination of three different materials: SiGe, N-doped HfO2 and MoOx, using the combination of two techniques: spectroscopic ellipsometry, and energy loss signal (ELS) of X-ray photoelectron spectroscopy (XPS). The determination of such physical properties is achieved through the hybridization of the two techniques based on multiple Tauc-Lorentz model, applied on the whole energy range of measurement.Such use of hybridized data demonstrates a new robust method to determine the band gap of the studied materials, together with the optical indices (refractive index and extinction coefficient) on a wide energy range (up to 40 eV). This method provides an extension of determination of the relevant physical quantities compared to each technique on their own.Moreover, this algorithm is tested on limit conditions, where the energy ranges of measurement of the two respective techniques presented no overlap. Yet the use of a unique physical model still allows us to calculate the different physical quantities even on the energy range where no measurement is performed, validating the semi-predictive nature of the hybrid technique. Additional measurements under different experimental configurations validate the extended scope of such hybrid technique.

Enhancement of the structural, optical, and dispersion performance of polyvinyl alcohol via coronene additive for optoelectronic applications

Composite films made of polyvinyl alcohol (PVA) filled with various coronene concentrations were fabricated via the solution casting method. Several characterization techniques were used to examine the prepared samples. The x-ray diffraction study shows decreasing semi-crystalline properties in PVA/coronene composites with increasing coronene levels, thereby improving charge carrier mobility and enhancing conductivity. The alterations in the chemical functional groups of the PVA/coronene composites were explored using Fourier-transform infrared spectroscopy (FTIR). The impact of coronene molecules on the optical characteristics of PVA was investigated in the spectral ranges of 190-2500 nm. PVA/coronene composite exhibits higher UV blocking in the 190-400 nm wavelength range, suitable for UV notch filters like laser blocking filters. By increasing the coronene filling ratio from 0 wt% to 3 wt%, both the indirect and direct optical band-gap of PVA films decreased from 5.19 eV and 5.77 eV to 3.85 eV and 5.18 eV, respectively. The single oscillator model (Wemple-DiDomenico) was used to explain the refractive index dispersion region. The extracted values of dispersion energy (Ed), oscillator energy (Eo), dielectric constant at infinite frequency (ε ∞), and lattice dielectric constant (ε L) of PVA/coronene composite samples increased from 0.78 eV, 2.41 eV, 1.32 and 1.41 to 13.44 eV, 12.22 eV 2.10 and 2.13, respectively. These changes in dispersion parameters are due to cross-linking between the PVA polymeric matrix and the coronene. As a result of these improvements, PVA/coronene films could be applied to flexible packaging applications and optoelectronic devices like solar cells or light-emitting diodes.

Effect of AlN/GaN supercycle ratio on properties of AlxGa1−xN films using super-cycle plasma enhanced atomic layer deposition

In this study, aluminum gallium nitride (AlGaN) films are prepared by supercycle plasma enhanced vapor deposition (PEALD) with trimethylgallium, trimethylaluminum, and NH3 plasma. The ratio of aluminum nitride (AlN) to gallium nitride (GaN) PEALD cycle number is varied to investigated its effect on film properties. The experimental results show that the growth per cycle is lower than that of the mixing rule prediction, and the Ga content dramatically drops with increasing the AlN cycle ratio. It is implied that AlN surface partly hinders the growth of GaN during supercycle deposition. The Ga:Al elemental ratio is found to be 1:1 at the AlN cycle ratio of 20%, beyond which the film transforms from Ga-rich to Ga-poor and is accompanied with increased Al-Al metallic bonds. The film with the 20% AlN cycle ratio also exhibits the least aggregated surface morphology. The elemental depth profile investigated using secondary ion mass spectroscopy indicates an uniform distribution of Ga, Al and N. The bandgap of supercycle PEALD AlGaN films can be tuned when the AlN cycle ratio is less than 20%. Moreover, the AlGaN film with 20% AlN cycle ratio shows a photoluminescence peak centered at 277 nm, agreeing with the bandgap of the film.

Effect of Cu, Co, and Pb doping on physical properties of ZnO Zinc Blende and Hexagonal mixed phases thin films prepared by spray pyrolysis

Here we report the preparation of the Zinc Blende ZnO phase mixed with a small ratio of the Wurtzite phase. The spray pyrolysis technique has been employed for all films deposited onto amorphous glass substrates. The XRD results revealed the formation of mixed ZnO Zinc Blende (ZB) and Wurtzite (WU) phases with the ZB phase as the predominant phase. The crystallite size of both phases had estimated using Scherer’s equation and both phases were found to have the same crystallite size. The FE-SEM images show the formation of grain sizes bigger than those recorded from Scherer’s equation. XPS results confirm the existence of doped elements in the deposited films with different ratios. The optical band gap of the pure film was estimated and found to be 3.24 eV. Upon doping the band gap optical has been decreasing to 3.2 eV for Cu-doped ZnO and 3.22 and 3.24 eV for Pb and Co-doped films. The refractive index dispersion was found to change from normal to anomalous behavior for a pure film as the wavelength increases. Cu and Pb-doped films show dispersion relation and Co-doped film shows normal behavior. Also, the high-frequency dielectric constant has been determined and found to decrease upon all doping elements as compared to pure film.