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Pure and silver doped ZnO thin films were successfully grown on glass substrates by spray pyrolysis technique. The effect of Ag doping different concentration (2, 4, 6 and 8 at.%) on the structural, surface morphological, electrical and optical properties of Ag:ZnO thin films were investigated by X-Ray diffraction (XRD), Scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), photoluminescence (PL) and Hall effect measurement respectively. The X-ray pattern results confirmed that the Ag:ZnO thin films were polycrystalline nature with the preferential orientation along (002) plane in wurtzite structure. The SEM image revealed that the surface morphology of the films nano flower shaped grains with Ag doping. The compositional analysis by EDS confirms the presence of Zn, O and Ag. The surface roughness of the films decreases with increase of silver doping concentration was investigated by Atomic force microscopy (AFM). Optical transmittance 85% and a minimum resistivity of 1.23 × 10−3 Ω cm, are achieved for films when Ag doped ZnO with 6 at.% and confirm that these films are suitable for transparent conductive oxide (TCO) applications.

Zinc Oxide thin films had been deposited on microscopic glass substrate using spray pyrolysis technique at different substrate temperatures. The X-ray diffraction pattern of the prepared films had shown the polycrystalline nature with the preferential orientation along (0 0 2) plane. SEM micrograph of the prepared films revealed the uniform distributions of the flowers shaped grains. The presence of zinc and oxygen is confirmed from the peaks at 1 keV, 8 keV and 0.44 keV using EDS analysis. The columnar arrangement of the grains with the average grain size ranging from 80 to 140 nm is observed from the AFM analysis. From the optical studies, the high transparency in the visible region with an average transmittance reaching values up to 80% is observed. The calculated values of Energy band gap Eg are found to vary from 3.06 eV to 3.26 eV with increase of substrate temperature from 325 °C to 425 °C. The rise and fall in the extinction coefficient is directly related to the absorption of light. A drastic increase of refractive index indicates the compactness of the prepared films. The photoluminescence spectra exhibited the emission peaks at 418 nm, 441 nm, 525 nm and 671 nm which were corresponding to violet, blue, green and red emission.

Highly oriented Zn doped TiO 2 thin films (0, 2, 4, 6 and 8 at%) were deposited by spray pyrolysis technique. X-ray diffraction analysis showed a strong orientation along (101) direction for 6 at% Zn with polycrystalline tetragonal anatase phase. Scanning electron microscopy observations revealed uniform distribution of spherical-shaped grains, whereas columnar arrangement of tetragonal-shaped grains with porous nature was revealed from atomic force microscopy. Transmittance spectra indicated a decrease in the energy band gap with increasing doping concentration; i.e. 3.55 up to 3.21 eV, attributed to grain refinement to the nanoscale regime. The optical constants such as refractive index and extinction coefficient as a function of wavelength, were determined; the low extinction coefficient values confirmed the good quality of the thin films. Photoluminescence spectra showed strong emissions at 423 and 437 nm with a weak emission at 505 nm, which confirmed the lesser defect density in 6 at% Zn film. The electrical properties studied by Hall Effect measurements revealed that the 6 at% Zn led to an increase in the carrier concentration, as well as an increase in the mobility with a least resistivity. The efficiency of dye sensitized solar cells, assembled by using natural dye extracted from Hibiscus Surattensis as sensitizer and Zn-doped TiO 2 nanocrystalline thin films as a photoelectrode, was found to be around 1.22%.

Copper doped tin sulphide (SnS: Cu) thin films have been prepared by the spray pyrolysis technique at the substrate temperature of 350 °C. The optical and electrical properties of the films were studied as a function of copper dopant concentration (up to 10 at.%). The optical measurements showed the energy band gap, refractive index and extinction co-efficient values varied with increase in Cu concentration and the PL spectra showed the strong emission peak around at 765 nm. The film has the lowest resistivity while higher carrier concentration and mobility were obtained at 8 at.% of Cu.

Semiconducting CdIn2Se4 thin films have been deposited on to the conducting glass substrates using pulsed electrodeposition technique. X-ray diffraction (XRD) shows the films are polycrystalline in nature having cubic crystal structure. Energy dispersive analysis (EDAX) spectrum of the surface composition confirms the nearly stoichiometric CdIn2S4 nature of the film. Atomic force microscope (AFM) shows that the deposited films are well adherent and grains are uniformly distributed over the surface of substrate. The surface roughness and grain size increased from 0.2 nm and 12 nm to 0.7 nm and 20 nm respectively with increase of duty cycle. The films are highly transparent in the visible region with an average transmittance reaching up to 80%, which indicates the better crystalline nature with less defects. The CdIn2Se4 thin films show band gap energies of the films decreased from 3.12 eV to 3.77 eV. Keywords: Structural studies, XPS, AFM, Optical properties and photosensitivity

Pure and In-doped ZnO thin films were deposited onto glass substrates by spray pyrolysis technique. XRD results showed that all films were polycrystalline in nature with the wurzite structure. A change in preferential orientation from (0 0 2) to (1 0 1) plane was observed with increase in content of Indium. A reduce in crystallite size was observed with increase of In content. The small sized grains with the porous nature of the film was observed from SEM analysis. AFM study depicted polycrystalline nature and uniformly distributed grains with small pores in the doped film. A decrease in band gap was noticed with increase in In content. The absence of green emission in PL spectra indicated the decreased oxygen defects. The decrease in the resistivity with increase of Hall mobility was noted for the doped film. A better antibacterial activity was observed against Staphylococcus aureus by doped ZnO thin film.

Titanium dioxide (TiO2) thin films had been deposited with various substrate temperatures by spray pyrolysis technique onto ITO substrates. All films exhibited polycrystalline nature with the preferred orientation along (101) plane. At the substrate temperature 450 °C, the film favored the formation of anatase phase. The higher substrate temperature (475 °C) favored the appearance of rutile structure. The SEM image of the film at substrate temperature (Ts=450 °C) showed high structural quality with the porous nature. The typical AFM image of TiO2 film deposited at the substrate temperature, 450 °C depicted the regular arrangement of fine closely packed tetragonal structured grains. The transmittance of the spectra exhibited above 85% with energy band gap of 3.6 eV. From the study of photoluminescence, the emission at 417 nm, 437 nm and with weak emission at 551 nm was observed, which confirmed the lesser defects in the samples. The electrical resistivity was found to be 6.856×10(1) Ω cm for the substrate temperature 450 °C. The efficiency of anatase TiO2 photoelectrode deposited at the substrate temperature 450 °C based cell was much higher than the efficiency of TiO2 photoelectrode deposited at the substrate temperature 475 °C based cell.

Pure and zinc-doped titanium dioxide (Zn-doped TiO2) thin films were deposited on indium tin oxide coated glass plates using spray pyrolysis technique. The XRD pattern revealed the formation of anatase TiO2 with the maximum intensity of (101) plane with doping of zinc. The morphological studies depicted the porous nature, with the uniform arrangement of small-sized grains (SEM). The presence of zinc confirmed the EDX spectra. High resolution transmission electron microscope revealed the agglomerated spherical-like morphology and the particle size in the range of 10–20 nm. It was observed that the average transmittance was about 85 % for the zinc doped TiO2 film, which decreased the energy band gap. The PL study showed the emission peak at 418 nm for the doped films. The low resistivity maximum carrier concentration and Hall mobility was observed in Zn doped TiO2 films. The prepared Zn doped TiO2 thin film was proposed as the promising photocatalyst for the degradation and decolorization of methylene blue dye. The efficiency of anatase TiO2 photoelectrode deposited at the substrate temperature 450 °C based cell was much higher than the efficiency of Zn doped TiO2 photoelectrode cell.

Aluminum-doped zinc oxide (ZnO:Al) thin films were deposited onto glass substrates using spray pyrolysis technique with the substrate temperature of 400 °C. X-ray diffraction analysis indicated that the films were polycrystalline with hexagonal wurtzite structure preferentially oriented along (002) direction. Surface morphology of the films obtained by scanning electron microscopy showed that the grains were of nanoscale size with porous nature for 6 at.% of Al. Atomic force microscopy observations revealed that the particles size and surface roughness of the films decreased with Al-doping. Optical measurements indicated that ZnO:Al (6 at.%) exhibited a band gap of 3.11 eV, which is lower than that of pure ZnO film, i.e. 3.42 eV. Photoluminescence analysis showed weak NBE emission at 396 nm for Al-doped films. The low resistivity, high hall mobility and carrier concentration values were obtained at a doping ratio of 6 at.% of Al. The effective incorporation of 6 at.% of Al into ZnO lattice by occupying Zn sites yielded a well-pronounced antibacterial activity against Staphylococcus aureus.

Titanium dioxide (TiO2) thin films had been deposited onto glass substrates at various substrate temperatures by spray pyrolysis technique. X-ray diffraction analysis of deposited TiO2 films exhibited nanocrystalline nature and preferentially oriented along (101) direction. Scanning electron microscopy depicted that the films were uniform and adherent to the glass substrate. The field emission scanning electron microscopy (FE-SEM) films, exhibiting almost spherical shape of nanosized particles, was observed. The size of particles of 9.2 nm was observed from high-resolution transmission electron microscopy analysis. The decreased surface roughness observed in atomic force microscopy was due to the decrease in grain size with increased substrate temperatures. All films exhibited a transmittance of about 80 % in the visible region. The direct band gap values were from 2.1 to 3.6 eV by increasing substrate temperature. The photoluminescence spectra measurements indicated that the intensity of emission peaks significantly varies with substrate temperature. Further, these TiO2 films showed effective antibacterial activity against tested pathogens. Photocatalytic activity of the TiO2 thin film was studied using an organic dye, methylene blue, under solar irradiation.

Undoped and zirconium doped indium oxide (ZrIO) thin films were deposited on glass substrate at a substrate temperature of 450 °C by spray pyrolysis method. The effect of zirconium (Zr) dopant concentration (0–11 at.%) on the structural, morphological, optical and electrical properties of n-type ZrIO films were studied. X-ray diffraction (XRD) results confirmed the polycrystalline nature of the ZrIO thin film with cubic structure. The grain size was decreased from 25 to 15.75 nm with Zr doping. The scanning electron microscopy (SEM) showed that the surface morphology of the films were changed with Zr doping. The surface roughness of the films was investigated by atomic force microscopy (AFM) and was found to be increased with the increasing of Zr doping percentage. A blue shift of the optical band gap was observed. The optical band was gap decreased from 3.50 to 3.0 eV with increase in Zr concentrations. Room temperature photoluminescence (PL) measurement of the deposited films indicated the incorporation of Zr in In2O3 lattice. The film had low resistivity of 6.4 × 10−4 Ω cm and higher carrier concentration of 2.5 × 1020 was obtained at a doping ratio of 7 at.%.

Pristine TiO2 and Sn-doped TiO2 thin films with different Sn doping levels (2, 4, 6 and 8 at.%) were deposited by employing a simplified spray pyrolysis technique. The XRD pattern of the films confirmed tetragonal structure with the polycrystalline nature. The films exhibited a pure anatase titanium dioxide (TiO2) with a strong orientation along (101) plane. The scanning electron microscopy image of 6 at.% Sn-doped TiO2 thin film depicted nanosized grains with porous nature. The atomic force microscopy study had shown the columnar arrangement of grains with the increase in particle size and surface roughness for 6 at.% Sn-doped TiO2 thin films. The optical transmittance was increased with the decrease in the optical energy band gap. The optical constants such as extinction coefficient and refractive index were determined. The intensity of the photoluminescence emission was observed at 398 nm for doped films. The resistivity decreased with the increasing carrier concentration and Hall mobility. The incorporation of Sn into TiO2 matrix yielded a well-pronounced antibacterial activity for Bacillus subtilis.

Transparent and conducting thin films of pure and Sn-doped ZnO (ZnO:Sn) were deposited onto ITO coated glass substrates by spray pyrolysis technique at 350 °C. Structural, morphological, optical, and electrical properties of the as-prepared thin films were characterized by X-ray diffraction, atomic force microcopy (AFM), Transmission electron microscopy, UV–Vis spectroscopy and photoluminescence, as well as Hall Effect, respectively. The results indicated that all the films were polycrystalline with a hexagonal wurtzite structure exhibiting preferential orientation along (002) direction up to 1 at.% of Sn and random orientation for higher doping. AFM study revealed that the grain size and roughness of the films decreased with increasing Sn doping concentration. The optical gap increased slightly from 3.37 to 3.48 eV due to Burstein–Moss effect. PL spectra showed a strong UV emission peak and a relatively weak green emission peak reflecting the crystalline nature and less oxygen defects, respectively. The electrical conductivity increased with increasing Sn doping concentration, but for higher doping concentration (>1 at.%), the conductivity decreased. The power conversion efficiency of DSSCs based on Sn doped-ZnO thin film exhibited higher efficiency (0.74 %) compared to pure ZnO film because of its large surface area for adsorption of dye molecules. This result indicates that Sn-doped ZnO film has promising application in the field of DSSCs, and the optimization of porous film fabrication condition is efficient for the improvement of ZnO based DSSCs performance.

ZnO thin films had been successfully prepared by spray pyrolysis (SP) technique on ITO/Glass substrates at different substrate temperature in the range 250–400 °C using Zinc acetylacetonate as precursor. The X-ray diffraction studies confirmed the hexagonal wurtzite structure with preferred orientation along (0 0 2) plane at substrate temperature 350 °C and the crystallite size was found to vary from 18 to 47 nm. The morphology of the films revealed the porous nature with the roughness value of 8–13 nm. The transmittance value was found to vary from 60% to 85% in the visible region depending upon the substrate temperature and the band gap value for the film deposited at 350 °C was 3.2 eV. The obtained results revealed that the structures and properties of the films were greatly affected by substrate temperature. The near band edge emission observed at 398 nm in PL spectra showed better crystallinity. The measured electrical resistivity for ZnO film was ∼3.5 × 10−4 Ω cm at the optimized temperature 350 °C and was of n-type semiconductor. The obtained porous nature with increased surface roughness of the film and good light absorbing nature of the dye paved way for implementation of quality ZnO in DSSCs fabrication. DSSC were assembled using the prepared ZnO film on ITO coated glass substrate as photoanode and its photocurrent – voltage performance was investigated.

A spray pyrolysis technique was used to deposit the silver doped tin sulfide (SnS:Ag) thin films on glass substrates at the substrate temperature of 350 °C. The variation in structural, optical and electrical properties of SnS with silver incorporation was investigated. The XRD spectra showed the improvement in crystallinity while increasing the doping concentration of Ag. The lower electrical resistivity of 8.63×10−1 Ω cm and the optical band gap of 1.33 eV were obtained at 8 at% of Ag.

Tin sulphide (SnS) thin films were deposited on glass substrate at different substrate temperature (Ts = 325 °C, 350 °C and 375 °C) by pyrolytic decomposition using stannous chloride and thiourea as precursor solutions. Also, indium-doped SnS thin films were prepared by using InCl3 as dopant source. The dopant concentration [In/Sn] was varied from 2 at% to 6 at%. The XRD analysis revealed that the films were polycrystalline in nature having orthorhombic crystal structure with a preferred grain orientation along (1 1 1) plane. Due to In doping, the orientation of the grains in the (1 1 1) plane was found to be deteriorated. Atomic force microscopy (AFM) measurements revealed that the surface roughness of the films decreased due to indium doping. The optical properties were investigated by measuring the transmittance characteristics which were used to find the optical band gap energy, refractive index and extinction coefficient. The energy band gap value was decreased from 1.60 to 1.43 eV with increasing In concentration. The photoluminescence (PL) measurements of thin films showed strong emission band centered at 760 nm. Using Hall Effect measurements electrical resistivity, carrier concentration and Hall mobility have been determined.

Thin films of tin sulfide were deposited onto glass substrates by pyrolytic decomposition using stannous chloride and thiourea as precursors. The properties of thin films based on deposition parameters such as substrate temperature ( T s ), molarity of precursor solution ( M ) and spray rates ( R ) were studied. The deposited films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy and Hall Effect measurements. The XRD patterns of the films exhibited polycrystalline nature with orthorhombic crystal structure. The crystallite size varied from 30 to 107 nm with the change of deposition parameters. The band gap, electrical resistivity values and the type of conductivity with respect to deposition parameters were also observed.

Bismuth doped tin sulfide (SnS:Bi) thin films were deposited onto glass substrates by the spray pyrolysis technique at the substrate temperature of 350 °C. The effect of doping concentration [Bi/Sn] on their structural, optical and electrical properties was investigated as a function of bismuth doping between 0 and 8 at%. The XRD results showed that the films were polycrystalline SnS with orthorhombic structure and the crystallites in the films were oriented along (111) direction. Atomic force microscopy revealed that the particle size and surface roughness of the films increased due to Bi-doping. Optical analysis exhibited the band gap value of 1.40 eV for SnS:Bi (6 at%) which was lower than the band gap value for 0 at% of Bi (1.60 eV). The film has low resistivity of 4.788×10−1 Ω-cm and higher carrier concentration of 3.625×1018 cm−3 was obtained at a doping ratio of 6 at%.

Titanium dioxide (TiO2) thin films have been deposited on microscopic glass substrate by spray p yrolysis technique. The effect of deposition parameters such as substrate temperature, molarity (precursor concentration) and solution spray rate on the structural, surface morphological and optical properties of the films ha ve been studied. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and UV-Vis spectroscopy. The XRD patterns indicated that the films have amorphous and polycrystalline structure and the size of the crystallite s have been changed from 9 to 48 nm. The optical band gap of the TiO2 films is determined to be about 3.40 to 3.65 eV to the change of deposition co nditions.

Thin films of antimony doped tin sulphide (SnS:Sb) with different antimony concentrations have been prepared by the spray pyrolysis technique at the substrate temperature of 350 °C. The physical properties of the films were studied as a function of increase in antimony dopant concentration (up to 10 at.%). The films were characterized by different techniques to study their structural, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature and having orthorhombic crystal structure with a preferred orientation in (1 1 1) direction. Due to Sb doping, the crystalline quality and the preferential orientation of SnS films were improved up to 6 at.% of doping concentration. However, when doping concentration was increased above 6 at.%, the crystalline quality and the preferential orientation of SnS films was deteriorated. Atomic force microscopy images revealed that the surface roughness of the films increased due to Sb doping. Optical measurements showed that the band gap values decreased from 1.60 eV to 1.15 eV with increase in Sb concentration. The photoluminescence spectra displayed that all the samples have an emission peak centered at 760 nm. At 6 at.% of Sb doping, the film has the lowest resistivity of 2.598 × 10−2 Ω cm while the carrier concentration was high.

Indium oxide (In 2 O 3 ) thin films are successfully deposited on microscopic glass substrate at different temperatures by spray pyrolysis technique using Indium acetate as precursor solution. The physical properties of these films are characterized by XRD, SEM, AFM, UV–visible, PL and Photo acoustic measurements. XRD analysis revealed that the films are polycrystalline in nature having cubic crystal structure with a preferred grain orientation along (2 2 2) plane. The average transmittance in the visible region is found to vary from 60% to 93% depending upon the substrate temperature. The complete vibrational analysis has been carried out and the optimized parameters are calculated using HF and DFT (LSDA, B3LYP and B3PW91) methods with 3-21G(d,p) basis set for In 2 O 3 . The fundamental frequencies are calculated and assigned according to the experimental frequencies. Furthermore, 13 C NMR and 1 H NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) technique with HF/B3LYP/B3PW91 methods on same basis set. A study of the electronic properties; absorption wavelengths, excitation energy, dipole moment, Kubo gap (HOMO and LUMO) and frontier molecular orbital energies, are performed by HF and DFT methods. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) is executed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the compound are calculated in gas phase.

Undoped and Indium doped tin disulphide (SnS2) thin films had been deposited onto glass substrates at Ts = 300 °C using spray pyrolysis technique under atmospheric pressure with stannous chloride, indium chloride and thiourea as precursors. The structural, optical and electrical properties of the deposited films were characterized. The XRD pattern revealed that the undoped and doped films had preferred orientation along (002) plane with hexagonal structure. FESEM micrographs had shown that morphologies of the films changed with indium doping. Optical constant such as refractive index (n), extinction coefficient (k), real and imaginary parts of dielectric constants were evaluated from transmittance and reflectance spectra in UV-Visible spectroscopy. The optical absorption data were used to determine the band gap energy and it was found to be 2.75 eV for undoped and 2.50 eV for indium doped films respectively. The room temperature dark resistivity was found to be 4.545 × 103 Ω-cm and 5.406 × 103 Ω-cm for undoped and In-doped films respectively.

In this work, the pulse electrodeposition technique has been employed for the first time to deposit SnSe films from a bath containing Analar grade 50 mM tin chloride (SnCl4) and 5 mM SeO2. The XRD profile of SnSe thin films deposited at different duty cycles indicate the peaks corresponding to SnSe. Atomic force microscopy studies indicated that the surface roughness increased from 0.5 to 1.5 nm with duty cycle. The transmission spectra exhibited interference fringes. The value of refractive index at 780 nm was 2.1, this value decreased to 1.95 with decrease of duty cycle. The room temperature resistivity increased from 0.1 to 10 Ωcm with decrease of duty cycle. Photo electrochemical cell studies were made using the films deposited at different duty cycles. For duty cycles greater than 15% photo output was observed. For a film deposited at 50% duty cycle, an open circuit voltage of 0.55 V and a short circuit current density of 5.0 mA cm−2 at 60 mW cm−2 illumination. Capacitance voltage measurements indicated Vfb = 0.67 V (SCE) and p type, carrier density = 6.98 × 1016 cm−3.

Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films.

Tin doped zinc oxide (ZnO:Sn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 400 °C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8 at.%) of tin. The XRD results had shown that the films were polycrystalline ZnO with hexagonal wurtzite type structure and the crystallites in the films were oriented along (0 0 2) direction. Surface morphology of the films obtained by scanning electron microscope (SEM) exhibited the change in morphology with doping concentration and porous nature for the film with 6 at.% of tin. Atomic force microscopy (AFM) revealed nanometer sized particles with decreased surface roughness for Sn doping. Optical analysis exhibited the band gap value of 2.8 eV for ZnO:Sn (6 at.%) which was lower than the band gap value for undoped ZnO film (3.2 eV). The resistivity of 6 at.% of Sn doped film was 1.28 × 102 Ω cm with increase in the hall mobility and carrier concentration. The ZnO and Sn doped ZnO thin films exhibited antibacterial activity against Staphylococcus aureus.

In this work, highly transparent conducting un-doped and Zn-doped In 2 O 3 thin films were prepared onto glass substrate using spray pyrolysis method. Structural, morphological, optical and electrical properties were characterized by using XRD, FT-IR, FT-Raman, SEM, AFM, UV–visible, PL and Hall Effect measurement techniques. X-ray diffraction analysis showed that the deposited films were polycrystalline with cubic structure having (2 2 2) as preferred orientation. SEM and AFM analyses showed smooth surfaces but the surface roughness of the films increased due to Zn doping. The average optical transmittance of the films was above 94% in the visible range. The optical band gap decreased from 3.62 to 3.28 eV with increasing Zn concentration. The photoluminescence spectra displayed violet-blue emission peaks at around 418–440 nm for all films. The electrical parameters like the resistivity, mobility and carrier concentration were found as 6.4 × 10 −4 Ω cm, 168 cm 2 /Vs and 9.4 × 10 20 cm −3 , respectively for In 2 O 3 :Zn film deposited at 9 at.%. The present results showed that the obtained thin films could be used as an optoelectronic material.

Zinc oxide films were doped with different concentrations of Ti on glass substrates at 400 °C by spray pyrolysis technique. The films exhibited single phase ZnO for low concentrations of Ti. Wurtzite ZnO peaks were observed at higher doping concentration with decreased crystallinity. Crystallite size, strain and dislocation density were evaluated from the X-ray diffraction data. Surface morphology of the films indicated that a remarkable decrease in grain size with increasing of Ti concentration. The band gap of the films was found to be increased from 3.20 eV to 3.32 eV as the concentration of Ti doping increases. The resistivity of the films decreased from 9 × 105 Ω cm to 9 × 104 Ω cm with the increase of Ti doping concentration. Both Raman spectroscopy and room temperature photoluminescence exhibited characteristic peaks that confirmed the formation of ZnO phase.

Indium oxide (In2O3) and titanium-doped indium oxide (ITiO) thin films were deposited onto glass substrates by the spray pyrolysis technique. The variations of the structural, optical and electrical properties with the titanium incorporation were investigated. The XRD profile of the films confirmed the cubic structure with preferred orientation along the (222) planes. The average crystalline size evaluated from the XRD profile lay in between 24.96nm and 34.47nm. The other crystallographic parameters namely, micro strain, dislocation density, and lattice constant had been estimated and reported. The average optical transmittance of the sample varied from 60% to 86% in the visible region. The optical band gap energy of the films varied from 3.68eV to 3.3eV, depending on the concentration of titanium. Topography and surface morphology of the films were performed by AFM, SEM and EDX analyses, respectively. It is observed that resistivity of the films decreases with increase of mobility for the doped film.

Thin films of tin sulphides (Sn x S y ) were deposited on glass substrates by spray pyrolysis technique using precursor solutions of SnCl 2 .2H 2 O and thiourea and InCl 3 at different substrate temperatures that vary in the range of 275 – 375°C. The physical properties of these films were characterized by using X-ray diffraction, Field Emission Scanning Electron Microscope, UV-Visible Spectrophotometer and Photoluminescence. The XRD pattern revealed that the undoped and doped films had preferred orientation along (002) plane with hexagonal structure. FESEM micrographs had shown that morphologies of the films were changed with doping of indium. The direct energy band gap value of undoped and indium doped SnS 2 thin films were found to be 2.7 eV and 2.5 eV respectively. Photoluminescence had shown the shift in the band towards the longer wavelength.

In this work, the pulse electrodeposition technique has been employed for the first time to deposit AgInSe 2 films. AgInSe 2 films were deposited by the pulse electrodeposition technique at room temperature from a bath containing Analar grade 10 mM silver sulphate, 50 mM indium sulphate and 5 mM SeO 2 . The deposition potential was maintained as − 0.98V (SCE). Tin oxide coated glass substrates (5.0 ohms/ sq) was used as the substrate. The duty cycle was varied in the range of 6 – 50 %. The XRD profile of the thin films deposited at different duty cycles indicate the peaks corresponding to AgInSe 2 . Atomic force microscopy studies indicated that the surface roughness increased from 0.8 nm to 1.7 nm with duty cycle. The transmission spectra exhibited interference fringes. The room temperature resistivity increased from 0.1 ohm cm to 10 ohm cm with decrease of duty cycle. Photoelectrochemical cell studies were made using the films deposited at different duty cycles. The photo output was observed to increase with duty cycle. For a film deposited at 50 % duty cycle, an open circuit voltage of 0.55 V and a short circuit current density of 5.0 mA cm−2 at 60 mW cm−2 illumination.

In this work, the pulse electrodeposition technique has been emeployed for the first time to deposit SnSe films. SnSe films were deposited by the pulse electrodeposition technique at room temperature from a bath containing Analar grade 50 mM tin chloride (SnCl 4 ) and 5 mM SeO 2 . The deposition potential was maintained as − 0.9V (SCE). Tin oxide coated glass substrates (5.0 ohms/ sq) was used as the substrate. The duty cycle was varied in the range of 6 – 50 %. The XRD profile of SnSe thin films deposited at different duty cycles indicate the peaks corresponding to SnSe. Atomic force microscopy studies indicated that the surface roughness increased from 0.5 nm to 1.5 nm. The transmission spectra exhibited interference fringes. The value of refractive index at 780 nm was 2.1, this value decreased to 1.95 with decrease of duty cycle. The room temperature resistivity increased from 0.1 ohm cm to 10 ohm cm with decrease of duty cycle. Photoelectrochemical cell studies were made using the films deposited at different duty cycles. For duty cycles greater than 15 % photo output was observed. For a film deposited at 50 % duty cycle, an open circuit voltage of 0.55 V and a short circuit current density of 5.0 mA cm−2 at 60 mW cm−2 illumination. Capacitance voltage measurements indicated Vfb = 0.67 V (SCE) and p type, carrier density = 6.98 × 1016/ cm3.