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In the present communication, we have reported the effect of substrate on electrodeposited iron diselenide thin films. The deposited films have been characterized by X-ray diffraction, Energy dispersive analysis by X-rays, Scanning electron microscopy, Ultraviolet Visible Infrared spectroscopic techniques for the determination of structural, morphological, compositional and optical properties. Structural properties indicated that the prepared films possess orthorhombic structure. The parameters such as crystallite size, strain, dislocation density and stacking fault probability are determined for the deposited films. Compositional analysis indicated that the prepared films found to be nearly stoichiometry. The band gap value of the deposited films is in the range between 1.03 and 1.08 eV.

A new type of lithium enriched cathode material Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 was synthesized by sol-gel method with citric acid as a chelating agent. The structural and morphological studies were systematically investigated through X-ray diffraction, SEM with EDS, FT-IR and Raman analyses. The crystallite size of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material was found to be 45 nm thereby leads to the feasible movement of lithium ion all through the material. FT-IR spectroscopy was used to confirm the metal-oxygen interaction in the prepared cathode material. The electrical properties of the Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 cathode material were studied by impedance and dielectric spectral analyzes. Li (Li0.05Ni0.6Fe0.1Mn0.25)O2 showed a maximum ionic conductivity of 10-6 S/cm at ambient temperature.

In this work, we have focused the effect of substrate on electrochemically grown copper oxide and copper sulfide thin films. The prepared films have been subjected to X-ray diffraction, scanning electron microscopy, Energy dispersive X-ray analysis, UV–Visible spectroscopic techniques for the determination crystalline nature, morphology, composition and optical properties. X-ray diffraction results indicated the deposited films exhibited cubic structure with most reflection along (110), (220) planes for copper oxide and copper sulfide. Scanning electron microscopy along with energy dispersive analysis by X-rays showed that films with uniform morphology and nearly stoichiometry have been obtained for film obtained on SnO2 substrate. Optical absorption and transmittance measurements showed that the deposited films exhibited band gap value of 2.28 and 2.45 eV for copper oxide and copper sulfide.

Zinc Oxide and Glucose capped Zinc Oxide nanoparticles have been prepared using modified chemical reaction method. X-ray diffraction analysis showed that the prepared samples possess polycrystalline nature with hexagonal structure. Surface morphology has been analyzed using scanning electron microscopy. The estimated value of band gap was found to be 3.41 and 3.87 eV for Zinc Oxide and Glucose capped ZnO respectively. Fourier Transform Infrared spectroscopic analysis has been carried out to find the chemical bond and elemental composition present in Zinc Oxide and Glucose capped Zinc Oxide.

Pure and 3%, 5%, and 7% molybdenum-doped cadmium oxide (CdO) thin films have been prepared on glass substrates preheated to 400°C using a spray pyrolysis technique, then analyzed using x-ray diffraction analysis, field-emission scanning electron microscopy, ultraviolet–visible spectroscopy, and photoluminescence and Hall measurements. The films were found to have polycrystalline nature with cubic structure. The crystallite size was calculated to be ∼ 12 nm for various doping concentrations. Doping improved the optical transparency of the CdO thin film, with the 5% Mo-doped film recording the highest transmittance in the optical region. The energy bandgap deduced from optical studies ranged from 2.38 eV and 2.44 eV for different Mo doping levels. The electrical conductivity was enhanced on Mo doping, with the highest conductivity of 1.74 × 103 (Ω cm)−1 being achieved for the 5% Mo-doped CdO thin film.

Ni-doped CeO2 thin films were prepared under Ar+ atmosphere on glass substrates using rf magnetron sputtering. To assess the properties of the prepared thin films, the influence of various amounts of Ni dopant on structural, morphological, optical, vibrational, compositional and magnetic properties of the CeO2 films were studied by using X-Ray diffraction (XRD), atomic force microscope (AFM), photoluminescence (PL), micro-Raman, X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM). XRD patterns for all the samples revealed the expected CeO2 cubic fluorite-type structure and Ni ions were uniformly distributed in the samples. AFM images of the prepared samples indicate high dense, columnar structure with uniform distribution of CeO2. Room-temperature photoluminescence (PL) and micro-Raman spectroscopic studies revealed an increase of oxygen vacancies with higher concentration of Ni in CeO2. XPS results confirm the presence of Ni2p, O1s and Ce and depict that cerium is present as both Ce4+ and Ce3+ oxidation states in Ce1−xNixO2 (x = 15%) thin film. Field dependent magnetization measurements revealed a paramagnetic behavior for pure CeO2, while a ferromagnetic behavior appeared when Ni is doped in CeO2 films. Doping dependent magnetization measurements suggest that the observed ferromagnetism is due to the presence of metallic Ni clusters with nanometric size and broad size distribution.

CuO thin films prepared by spray pyrolysis method has wide range of applications. CuO thin films were coated on glass substrate at various temperatures such as 250, 350, 400, and 500 °C by spray pyrolysis. Thin films prepared were characterized by various techniques such as X-ray diffraction, SEM, UV–visible spectroscopy, PL and Hall measurements. XRD diffraction patterns reveal that the films are polycrystalline in nature exhibiting monoclinic structure. The prominent peak corresponds to (200) plane and the corresponding calculated crystallite size varies from 4 to 7 nm. SEM images exhibit grains of uniform size. It is found that the optical absorbance decreases with the increase in temperature and the optical energy band gaps vary from 2.22 to 2.75 eV for various substrate temperatures. Electrical studies done using Hall measurement system show that the copper oxide films are p-type semiconductors with carrier concentration in the order of 1016 cm−3. The electrical resistivity of the copper oxide films obtained was in the range 3.689 × 10−3 to 8.538 × 10−3 Ω cm. Hence, the CuO film is suitable for solar cell applications.

Cobalt-doped cerium dioxide thin films exhibit room temperature ferromagnetism due to high oxygen mobility in doped CeO 2 lattice. CeO 2 is an excellent doping matrix as there is a possibility of it losing oxygen while retaining its structure. This leads to increased oxygen mobility within the fluorite CeO 2 lattice, leading to formation of Ce 3+ and Ce 4+ species. Magnetic ceria materials are important in several applications from magnetic data storage devices to magnetically recoverable catalysts. In this paper, the room temperature ferromagnetism of rf sputtered Co doped CeO 2 thin films is reported whereas undoped CeO 2 thin films exhibit paramagnetic behavior. The ferromagnetic properties of the Co doped films were explained based on oxygen vacancies created by Co ions in Ce sites. This is further supported by X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Raman. Change in surface morphology due to Co doping of the samples were analyzed using atomic force microscopy (AFM).

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.

Zn 1− x Ni x O nanoparticles were synthesized by co-precipitation method. The crystallite sizes of the synthesized samples found to decrease from 38 to 26 nm with increase in nickel concentration. FTIR spectra confirmed the presence of Zn O stretching bands at 577, 573, 569 and 565 cm −1 in the respective ZnO NPs. Optical absorption spectra revealed the red shifted and estimated band gap is found to decrease with increase of Ni doping concentration. The PL spectra of all the samples exhibited a broad emission at 390 nm in the visible range. The carriers (donors) bounded on the Ni sites were observed from the micro Raman spectroscopic studies. Pure and Ni doped ZnO NPs showed significant changes in the M–H loop, especially the diamagnetic behavior changed into ferromagnetic nature for Ni doped samples. The antiferromagnetic super-exchange interactions between Ni 2+ ions is increased in higher Ni doped ZnO NPs and also their antibacterial activity has been studied.

In this paper, the structural and magnetic behavior of Ni/Mn co-doped ZnO nanoparticles (NPs) synthesized by co-precipitation method are presented. Powder X-ray diffraction data confirm the formation of a single phase wurtzite type of ZnO structure for all the synthesized Ni, Mn doped and co-doped ZnO nanoparticles. The average crystallite size of NPs is found to be 26–38 nm. FTIR and UV spectroscopic results confirm the incorporation of the dopant into the ZnO lattice structure. Photoluminescence intensity varies with doping due to the increase of oxygen vacancies. Furthermore, M-H curve demonstrates that the Ni/Mn co-doped ZnO NPs possess obvious ferromagnetic characteristics at room temperature. Our study enhances the understanding of the novel performances of transition metal co-doped ZnO NPs and also provides possibilities to fabricate spintronic devices.

Copper tin sulphide nanoparticles have been prepared by solution growth technique at various ethylenediamine concentrations. Prepared samples have been characterized using x-ray diffraction, fourier transform infrared, Raman and scanning electron microscopy techniques. x-ray diffraction results revealed that the prepared samples are nanocrystalline in nature with tetragonal structure. Fourier transform infrared spectroscopy analysis results showed the presence of Cu-O, Sn-O and Sn-S vibrations in the wavenumber range between 450 and 620 cm-1. Vibrational symmetry of prepared samples have been analyzed using Raman spectroscopy. Scanning electron microscopy analysis indicated the formation of flower like nanocrystals for samples prepared at various Ethylenediamine concentrations.

Pure and Al doped CdO thin films were coated on glass substrate at 400 °C by spray pyrolysis method for various aluminium concentrations (3, 5, 10 and 15 wt%). Al doped CdO thin films were characterized by various techniques such as X-ray diffraction, SEM, UV–visible spectroscopy and Hall measurements. XRD diffraction patterns reveal that the films are polycrystalline in nature exhibiting face centered cubic structure. The prominent peak corresponds to (200) plane and the corresponding calculated crystallite size varies from 12 to 18 nm. SEM images show that the films exhibit grains of uniform size which are agglomerated for films with higher dopant concentration. It is found that the optical transmittance decreases with the increase in Al concentration and the optical energy band gaps vary from 2.08 to 2.49 eV for various Al doping concentration levels. Electrical studies done using Hall measurement system exhibit that the undoped and Al doped CdO films are n-type semiconductors with carrier concentration in the order of 1021 cm−3. The electrical resistivity of the Al:CdO films ranges from 4.903 × 10−3 to 9.358 × 10−3 Ω cm.

Tungsten oxide nanostructures were developed on indium tin oxide coated glass substrates by modified thermal evaporation process without using catalyst and vacuum. Depending on the substrate temperature and vapor concentration, different nanostructures like rod, sheet and pyramid were formed. Morphology, phase structure and crystallinity of the nanostructure films were characterized by Scanning electron microscope (SEM), X-ray diffraction (XRD), Raman spectroscopy and HR-TEM. The samples were investigated under dark current and photocurrent and in H2SO4 aqueous solution as a function of applied potential. The saturated photocurrent density of tungsten oxide was found to be ≈14.4 μA cm−2. The films were also investigated as resistive gas sensor for ethanol gases (10–50 ppm) at room temperature. The response and recovery time were also determined.

CeO 2 and Ni–CeO 2 thin films with cubic fluorite structure were prepared by rf magnetron sputtering. Crystallinity and optical properties of the prepared thin films were studied using X-ray diffraction, UV–vis and Photo Luminescence analysis. Vibrational and magnetic properties of the films were analysed through Raman and VSM analyses. The results from XRD and Raman spectroscopy indicate that doped Ni species were dispersed on the ceria surface. Room temperature magnetic measurements reveal paramagnetic nature of pure CeO 2 thin films and ferromagnetic nature with reasonable saturation magnetisation (4.03×10 −5 emu/cm 3 ) of Ni doped CeO 2 thin films. It is believed that the ferromagnetic contributions exhibited in the M–H loops originate from the absorptive oxygen on the surface rather than the oxygen vacancies in the lattice.

The etching process of Porous Silicon has been carried out using an electrochemical oxidation technique. Oxidized samples were immobilized with -Leucine, DL-Iso Leucine and DL-Nor Leucine solutions. Surface morphology and optical properties of the samples have been analyzed using scanning electron microscopy and optical absorption analysis techniques respectively. The bonding characteristics on the surface before and after amino acid deposition have been studied using fourier transform infrared spectroscopy. Photoluminescence spectroscopy was employed to determine the enhancement in wavelength shift of the etched porous silicon.

Highly oriented thin films of Al doped ZnO (Al:ZnO) and Cu co-doped Al:ZnO (Cu/Al:ZnO) thin films were successfully deposited by sol–gel spin coating on glass substrates. The deposited films were characterized using X-ray diffraction analysis and found to exhibit hexagonal wurtzite structure with c-axis orientation. SEM images revealed that hexagonal rod shaped morphologies were grown perpendicular to the substrate surface due to repeated deposition process. High transmittance values were observed for pure ZnO compared to Al:ZnO and Cu/Al:ZnO thin films. The band gap widening is caused by the increase of carrier concentration, which is believed to be due to Burstein-Moss effect due to Al and Cu doping. PL spectra of Cu/Al:ZnO thin films indicate that the UV emission peaks slightly shifted towards lower energy side. XPS study was carried out for Zn0.80Al0.10Cu0.10O thin films to analyze the binding energy of Al, Cu, Zn and O. Magnetic measurement studies exhibited ferromagnetic behavior at room temperature, which may be due to the increase in copper concentration in the doped films. The ferromagnetic behavior can be understood from the exchange coupling between localized ‘d’ spin of Cu ion mediated by free delocalized carriers.

Antimony doped tin disulphide (SnS 2 :Sb) thin films have been prepared by the spray pyrolysis technique atthe substrate temperature of 300 1C. The properties of the films were studied as a function of antimonydopant concentration (up to 10 at%). The XRD analysis revealed that the films were polycrystalline in natureand having hexagonal crystal structure with a preferred orientation along (002) direction. The optical energyband gap values were decreased from 2.50 eV to 2.05 eV with increase in Sb concentration and the PLspectra showed strong emission peak around at 470 nm. The film has the lowest resistivity of1.088 210 Ω cm while higher carrier concentration was obtained at 8 at% of Sb.& 2015 Elsevier B.V. All rights reserved. 1. IntroductionTin disulphide (SnS 2 ) is considered to be one of the most usefulIV–VI group semiconducting tin chalcogenides which has foundapplications in opto-electronic devices, a part of solar collectors,etc. It was first synthesized some 200 years ago [1] and it has morethan 70 polytype structures [2]. It is a layered semiconductor withCdI

Cadmium Sulfide and Ferrous doped Cadmium Sulfide thin films have been prepared on different substrates using an electrodeposition technique. Linear sweep voltammetric analysis has been carried out to determine deposition potential of the prepared films. X-ray diffraction analysis showed that the prepared films possess polycrystalline nature with hexagonal structure. Surface morphology and film composition have been analyzed using Scanning electron microscopy and Energy dispersive analysis by X-rays. Optical absorption analysis showed that the prepared films are found to exhibit Band gap value in the range between 2.3, 2.8 eV for Cadmium Sulfide and Ferrous doped Cadmium Sulfide.

Trivalent neodymium doped ZnO (Zn1−xNdxO, x = 0.0, 0.03, 0.06 and 0.09) nanoparticles (NPs) synthesized by co-precipitation method with improved optical and antibacterial performance is reported. X-ray diffraction pattern indicates most of Nd3+ ions are incorporated in Zn2+ ions of ZnO lattice and hence there is no secondary peak of NdO3 in synthesized ZnO NPs. Fourier transform infrared spectroscopy analysis of synthesized NPs exhibits similar patterns in Zn/Nd–O bands observed at 480 cm−1. High resolution scanning electron microscopy images revealed the formation of spindle like morphology and the incorporation of Nd ions is confirmed by energy dispersive spectra analysis. UV–visible absorption spectra of pure and Nd doped ZnO NPs showed the variation of the band gap in the range of 3.06–2.65 eV. Raman analysis confirmed the formation of wurtzite structure of NPs was distorted due to Nd substitution in ZnO matrix. X-ray photoelectron spectroscopy confirmed the Nd incorporation in the ZnO lattice as Nd3+. The prepared Nd doped ZnO NPs showed potential application in antibacterial activities.

Zinc oxide (ZnO) thin films were deposited by spin coating technique onto glass and fluorine doped tin oxide (FTO) conductive substrates. The effect of the Pedalium Murex (P. Murex) leaf extract on their structural, morphological, lattice dynamic and optical properties was investigated. X-ray diffraction studies revealed that the prepared thin films were polycrystalline. The crystalline size, lattice parameter, position parameters, bond length and texture coefficient were estimated from XRD studies. Morphological variations (cordillera, backbone and tree like structure) were observed for films coated with different quantity of extract. Lattice dynamics and defect studies were investigated using micro Raman spectroscopy, which revealed the presence of oxygen vacancies and zinc interstitial in backbone like structure. The excitation and emission spectra revealed that the optical quality of the ZnO thin films depends on defect concentration and excitation energy. Variations in intensity were observed for violet to green emission with deceasing excitation energy. The transmittance spectra of the prepared thin films were recorded using UV–visible spectroscopy. The film prepared with 0.01 ml extract exhibited low transmittance and band gap compared to other films. J–V curves were recorded for film deposited with 0.01 ml extract using polymer and liquid electrolyte as an electrolyte. The effect of the internal resistance was studied for the film deposited with 0.01 ml extract. The open circuit voltage (Voc), short circuit current density (Isc) and efficiency (η) of the constructed DSSC were determined.

DBSA (Dodecylbenzene sulfonic acid)/PSS (Polystyrene sulfonic acid) doped polypyrrole composites were synthesized by in-situ chemical oxidative polymerization method with 0 to 5°C reaction temperature for 24 h. The particle size distribution of DBSA and PSS doped polypyrrole composites were found at 78 nm, 66 nm, 85 nm, 120 nm and 173 nm for different weight ratios of PSS. The presence of sulfur and higher doping level was confirmed by energy dispersive X-ray analysis. The mass percentages of sulfur were found in 17.94%, 34.41%, 40.87%, 44.9% and 48.16% for various weight ratios of PSS. The SEM study shows the granular morphology and aggregation of polypyrrole composites. Thermal stability improves with higher concentration of PSS. FTIR study confirms the presence of dopants in the composite structure. The UV-study reveals the π→π* transition in benzenoid rings of DBSA and presence of PSS. The conductivity of polypyrrole composite increases maximum upto 2.5 wt% of PSS and then decreases with increasing PSS content.

In this paper, we report the structural, optical and magnetic properties of nano crystalline samples of Zn1−x(TM)xO (TM = Ni, Co and x = 0, 0.05, 0.10 and 0.15) synthesized by co-precipitation method. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence (PL), micro-Raman, and vibrating sample magnetometer (VSM). It is observed from XRD patterns that all the samples reveal polycrystalline hexagonal wurtzite structure without any extra phase and average particle size decreased with increasing transition metal (TM) doping concentration. FTIR spectrum has been used to confirm the functional group of Ni–O and Co–O bond. SEM images demonstrated the grain like morphologies of TM doped ZnO nanoparticles (NPs). PL spectra of all samples exhibited a broad emission in the visible range. The carriers (donors) bounded on the TM sites were observed from the micro Raman spectroscopic studies. TM doped ZnO NPs showed significant changes in the M–H loop where the diamagnetic behavior of ZnO changes to ferromagnetic nature when doping with Ni and Co ions.

ZnO nanostructures such as nanoparticles, nanorods, nanotubes and nanoplates were prepared by the novel chemical solution route using different combinations of precursors such as zinc nitrate [Zn(NO3)2·6H2O] and sodium hydroxide [NaOH], zinc nitrate [Zn(NO3)2·6H2O] and hexamethylenetetramine (HMT) (C6H12N4), and zinc acetate [Zn(CH3COO)2·2H2O] and NaOH at low temperature. The effects of temperature and bath concentration for the synthesis of various ZnO nanostructures have been studied. Synthesized powders were characterized by X-ray diffraction, scanning electron microscope and photoluminescence. The crystalline structure, size and shape of the synthesized particles have been analyzed. Energy band gap values and photoluminescence emissions of the nanostructures were found to change according to the kind of the particles. Rod shaped ZnO have been obtained from the combination of zinc nitrate and HMT. The synthesized ZnO nanorods were aligned between lithographically patterned finger type metal contacts and their current–voltage response were measured.

Cerium oxide (CeO2) thin films were prepared by rf magnetron sputtering (PVD) technique onto glass substrates at a pressure of 3 × 10−4 mbar of Ar+ atmosphere. The thickness of deposited CeO2 films ranges from 380 to 590 nm. X-ray diffraction studies on the films showed that the films are polycrystalline in nature. The crystallite size (D), dislocation density (δ) and micro-strain (e) were evaluated from XRD patterns. The obtained micro-strain and dislocation density of the films were found to be ~10−3 and ~1016 lines/m2 respectively, along with a marginal increase in crystallite size from ~6 to ~9 nm. The experimental diffraction values of the films agreed with the standard values. The optical properties of cerium oxide films were studied in the wavelength range 325–900 nm. Optical absorption, extinction coefficients, refractive index and optical conductivity were evaluated from optical measurements. The films are found to be highly transparent in visible region and exhibits low reflectance in the ultraviolet region. The optical band gap of the films was found to decrease from 3.53 to 3.45 eV, with the increase of film thickness. The defects were found to increase with the increase of rf power. Emission bands like UV, weak blue, blue, blue–green and green bands were observed from PL spectra of CeO2 thin films. Raman active mode (F2g) of CeO2 thin films was observed at 466 cm−1 and films deposited at higher rf power show increased line width as well as peak intensity in Raman spectra. Rf power induced formations of flower like morphology were observed in SEM images. The surface roughness of CeO2 thin films was increased from 2.9 to 7.7 nm with the increase of rf power as ascertained from AFM images and the results are discussed.

In this paper, we present the structural, morphological, optical and magnetic properties of Zn1−x A x O (A = Ni, Co and x = 0.20 mol%) and Zn0.80Ni0.10Co0.10O nanoparticles synthesized by a chemical co-precipitation method. Powder X-ray diffraction data confirm the formation of a single-phase wurtzite-type ZnO structure for all the samples. FTIR and EDS measurements ensure that the divalent Ni and Co ions are incorporated in the wurtzite host matrix without any impurity phase. Photoluminescence and Raman spectra indicate the presence of donor defects and oxygen vacancies in the prepared samples. In VSM analysis, undoped ZnO nanoparticles exhibit diamagnetic behavior at room temperature. A systematic increase in ferromagnetic moment (~0.70 emu/g) is observed for Ni-, Co-doped and Co co-doped Ni/ZnO at 300 K. The exchange interaction between delocalized carriers and the localized ‘d’ spins of Ni and Co ions is predicted as the cause of the room temperature ferromagnetism.

We report systematic studies of the magnetic properties of Ni and Mn co-doped ZnO nanoparticles prepared by co-precipitation method. Structural characterization reveals that Ni and Mn ions substituted into ZnO lattices without any secondary phases formation. Photoluminescence and Raman spectra shows that the Ni/Mn were doped into the ZnO lattice resulting slight shift in near-band-edge emission. Moreover, the novel Raman peak at 586 cm−1 indicates two kinds of cations via doping that could affect the local polarizability. Magnetic measurements of the nanoparticles exhibits ferromagnetic behavior at room-temperature.

Nanoflake-structured NiO were synthesized by a microwave assisted method without the use of additives. The cubic phase of NiO nanoparticles with increasing crystalline nature for higher microwave power is ascertained by X-ray diffraction studies. Previous reports revealed that hexagonally structured β-Ni(OH)2 was completely transferred into the cubic phase of NiO around 350 °C, confirmed by using thermal analysis (TG/DTA). In our present work, the size and morphology of nanoparticles are ascertained from transmission electron microscopy (TEM) analysis. Flake-like morphology with uniform size, shape and less agglomerated structure formation is obtained for 900 and 600 W of microwave power used for the synthesis of NiO samples. The effect of microwave power used for the synthesis of NiO nanoflakes was analyzed by studying the magnetic and electrochemical behavior of NiO nanoflakes. Room temperature magnetic measurements revealed the small ferromagnetic nature of NiO nanoparticles. It was observed that the samples synthesized at higher microwave power exhibited divergence behavior below 300 K in FC and ZFC measurements, which results superparamagnetic behavior. An enhanced supercapacitor performance with higher specific capacitance values was determined for NiO nanoflake samples synthesized at (25)600 W and 900 W of microwave power.

Preparation of n-ZnO/p-Si heterostructures using solution-synthesized ZnO nanowire films and their photovoltaic characterization is reported. The solution-grown ZnO nanowire film is characterized using scanning electron microscope, electron dispersive x-ray, and optical absorption studies. Electrical and photovoltaic properties of the fabricated heterostructures are studied using e-beam-evaporated aluminum as metal contacts. In order to use transparent contact and to simultaneously collect the photogenerated carriers, sandwich-type solar cells were fabricated using ZnO nanorod films grown on p-silicon and indium tin oxide (ITO) coated glass as ITO/n-ZnO NR/p-Si. The electrical properties of these structures are analyzed from current-voltage (I−V) characteristics. ZnO nanowire film thickness-dependent photovoltaic properties are also studied. Indium metal was also deposited over the ZnO nanowires and its effects on the photovoltaic response of the devices were studied. The results demonstrated that all the samples exhibit a strong rectifying behavior indicating the diode nature of the devices. The sandwich-type ITO/n-ZnO NR/p-Si solar cells exhibit improved photovoltaic performance over the Al-metal-coated n-ZnO/p-Si structures. The indium deposition is found to show enhancement in photovoltaic behavior with a maximum open-circuit voltage (Voc) of 0.3 V and short-circuit current (Isc) of 70×10−6 A under ultraviolet light excitation.