X-ray Photospectroscopy Research Articles

Structural and Optical Properties of ZnCoO Thin Film Prepared by Electrodeposition

An oxide diluted magnetic semiconductor, Co doped ZnO thin film was successfully fabricated by cathodic electrodeposition method. X-ray diffraction studies demonstrate that the ZnCoO thin film indicates that the wurtzite structure. X-ray photospectroscopy studies suggested Co ions have a chemical valence of 2+. Optical absorption spectrum further confirmed Co ions have been doped into ZnO crystal lattice successfully with substituting positions of Zn ions. In photoluminescence spectrum, the UV emission band shifted to low energy side because of the doping effect.

Remove the Residual Additives toward Enhanced Efficiency with Higher Reproducibility in Polymer Solar Cells

Undesirable efficiency reproducibility was sometimes observed in fabrication of high performance polymer solar cell devices incorporating high boiling point additives. The anomalous results originated from the slow drying of additives not only reduced the controllability of device performance but also impeded the studies of device physics and material design. How to remove the residual additives and achieve stable interface properties is crucial for both the academic and industrial community. Herein, we demonstrated that the morphological stability is enhanced and efficiency reproducibility is increased obviously from 7.07 ± 0.27% to 7.53 ± 0.12% after spin-coating inert solvents for the PBDTTT-C-T/PCBM system. The relationship between processing conditions and photovoltaic performance was well explored and demonstrated via multiple techniques including atomic force microscopy, Kelvin probe force microscopy, transmission electron microscopy, and X-ray photospectroscopy. Most importantly, this method was s...

Resistance to fire of curable silicone/expandable graphite based coating: Effect of the catalyst

The fire performance of two curable-silicone based coatings containing 25% expandable graphite (EG) are evaluated in hydrocarbon fire scenario (standard UL1709) using a lab-scale furnace test. In this paper, the influence of the catalyst on the fire performance are investigated. Two organometallic titanium based- and tin based catalyst are used to make the curable silicone crosslink. When titanium based catalyst is used, the fire performance are higher and the mechanical properties of the char is better than that when tin is used as catalyst. To explain this surprising different fire behavior, the two residues after the furnace test were analyzed by X-ray photospectroscopy. It has been demonstrated that in the case of titanium based catalyst, the char is composed of graphite embedded by crosslinked silicone structure compare to linear silicone structure in the case of tin based catalyst. The two silicone resins were characterized by Fourier Transform Infrared spectroscopy, 29Si NMR, thermogravimetric analyses, EPMA (electron probe microanalyses). It was highlighted that the tin migrates into the surface during the crosslinking of the matrix leading to a low thermal stability and, thus, low fire performances. Whereas, when titanium based catalyst is used, it participates to the silicone network with the formation of Si–O–Ti bounds increasing the thermal stability of the matrix and so enhancing the fire performance of the silicone/EG based coating.

Hydrophilic modification of HDPE microfiltration membrane by corona-induced graft polymerization

Hydrophilic modification of high-density polyethylene membrane was performed with the introduction of peroxide onto the membrane surface by corona discharge treatment, followed by graft polymerization with acrylic acid. The surface graft polymerization was confirmed by attenuated total reflection-infrared and X-ray photo spectroscopy. Surface hydrophilicity was investigated by measuring the contact angles and moisture adsorption of the modified membrane. The results indicated that the modified membrane showed a significant increase in hydrophilicity. And water flux of the film increased from 102 L/m2 h of the virgin film to 200 L/m2 h of the grafted film, while the bovine serum albumin solution flux of the membrane increased from 43 L/m2 h of the virgin film to 98 L/m2 h of the modified membrane.

A dual-functional double-layer film with indium-doped ZnO nanosheets/nanoparticles structured photoanodes for dye-sensitized solar cells

A double-layer film composed of an upper-layer of indium-doped ZnO (IZO) nanosheets and a lower-layer of IZO nanoparticles structure (designated as DL-NS,s/NP,s:IZO) has been successfully synthesized by a simple two step electrospray method and studied as the dye-sensitized solar-cell (DSSCs) electrodes with the aim of developing a cost-effective alternative fabrication method and improving the performance of ZnO-based DSSCs. The XRD patterns demonstrated that the films exhibited the hexagonal wurtzite structure with preferential orientation along the (0 0 2) crystal plane and all the peaks slightly shifted toward the larger angle side due to the indium (In) doping. The composition of the doped ZnO films was confirmed with the help of X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS) and X-ray photospectroscopy (XPS). The upper-layer made of upright-standing IZO nanosheets (NS,s:IZO) acts as scattering centers to utilize more light as well as the direct pathway for the electrons to move towards the electrodes. The lower-layer composed of nonporous IZO nanoparticles increases the dye adsorption and also allowed for the suppression of the recombination of injected electrons. It was found that the DL-NS,s/NP,s:IZO film could significantly improve the efficiency (6.9%) of DSSCs owing to its enhanced light-scattering capability as well as intrinsic components of films, the photon-to-electron transfer process of the cells and relatively high surface area. This efficiency was significantly improved over the 4.8% obtained for double light-scattering-layer with DL-NS,s/NP,s:ZnO film and was also higher than the 3.2% achieved for single-layer of NP,s-IZO film. The fabricated cells showed highly durable cell performance, even after 40 days under atmospheric conditions. The efficiency achieved for the best DSSCs in this work is the highest ever reported value for a double light-scattering-layer ZnO film-based DSSCs.

An atmospheric pressure-based electrospraying route to fabricate the multi-applications bilayer (AZO/ITO) TCO films

A bilayer film composed of an upper-layer of aluminum-doped ZnO (AZO) film and a lower-layer of tin-doped indium oxide (ITO) film (designated as AZO/ITO) has been successfully fabricated using an atmospheric pressure-based electrospraying method and studied as an excellent transparent electrode, efficient field-emitter and the dye-sensitized solar-cell (DSSC) electrodes in order to develop a cost-effective alternative fabrication method. The morphological, optical and electrical properties were examined for the single layer of an ITO, an AZO and the bilayer AZO/ITO film. The composition of the films was confirmed with the help of energy-dispersive spectroscopy (EDS) and X-ray photospectroscopy (XPS). The bilayer AZO/ITO film presented an enhanced optical transparency of 95% with improved electrical performance, exhibited a resistivity of 9.3 × 10−5 Ω cm and a mobility of 49.5 cm2 V−1 s−1 compared to single layer TCO films that might be useful for optoelectronic devices. Moreover, the lowest turn-on field of ∼3.8 V μm−1, and highest emission current density of 3.9 mA cm−2 was obtained for bilayer AZO/ITO film under the field of 7.6 V μm−1, and the highest field enhancement factor (β) was estimated to be 3315 ± 2, compared with AZO and ITO single layer films. Furthermore, films exhibit good long period emission current stability with a variation of less than 4% during 30 h under a field of 7.6 V μm−1. For DSSCs, the photoanode composed of AZO film only showed a power conversion efficiency (PCE) as low as 0.57% with a short-circuit photocurrent density (JSC) of 2.5 mA cm−2 and an open-circuit voltage (VOC) of 425 mV. The photoanode with ITO film only exhibited higher PCE (0.84%) because of higher JSC (4.0 mA cm−2), whereas VOC (375 mV) was lower than that of AZO film. Compared to AZO and ITO single layer films, the bilayer structured AZO/ITO film demonstrated much higher PCE (2.4%) because of both higher JSC (7.4 mA cm−2) and VOC (600 mV). Addition of an AZO layer over the ITO layer significantly improved the electron transport and lifetime compared to the ITO only film. One order of magnitude slower charge recombination rate for the bilayer film than for the ITO film was found to be a major factor for the improved efficiency. The fabricated cells show highly durable cell performances, even after 40 days under atmospheric conditions. The proposed atmospheric pressure-based electrospraying film fabrication method was well suitable for the deposition of bilayer AZO/ITO films which found multi-applications as an excellent transparent electrode, efficient field-emitter and improved DSSC when compared with other vacuum-based methods.

Retracted Article: Enhanced photoluminescence, Raman spectra and field-emission behavior of indium-doped ZnO nanostructures

Indium-doped (In-doped) ZnO nanostructures with four different morphologies, namely nanochips, nanotripods, nanorods, and nanodisks, have been successfully synthesized by a simple hydrothermal method. The effects of indium dopant and various morphologies on the structural, optical and field-emission properties of these ZnO nanostructures were investigated. The XRD patterns demonstrated that the In-doped ZnO nanostructures exhibited the hexagonal wurtzite structure with preferential orientation along the (0 0 2) crystal plane, and a slight difference in lattice parameters was detected among the samples with various morphologies. The doped nanostructures were found to be single crystals grown along the c-axis. The composition of the doped ZnO nanostructures was confirmed by X-ray diffraction (XRD), X-ray photospectroscopy (XPS), and energy-dispersive spectroscopy (EDS). The photoluminescence (PL) spectra of doped ZnO nanostructures having a blue-shift in the UV region show a prominent tuning in the optical band gap, without any significant peak relating to intrinsic defects. From Raman spectra, the 437 cm−1 mode corresponds to the E2 mode for wurtzite ZnO crystals with very sharp features which revealed the better crystallinity of samples. The lowest turn-on field of the field-emission was found to be ∼2.5 V μm−1 and the highest emission current density of 1.13 mA cm−2 was also obtained for In-doped ZnO nanochips under a field of 6.3 V μm−1. The field enhancement factor β was estimated to be 10 640 ± 3 in the case of doped nanochips, which was much higher than that of any previous report. Moreover, the doped ZnO nanostructures exhibit good long period emission current stability with a variation of less than 5% during 25 h under a field of 6.3 V μm−1. The superior field-emission properties were attributed to the better morphologies, In-doping and better crystallinity of In-doped ZnO nanostructures.

A New Purification Technique for Single-Walled Carbon Nanotubes by Interaction with Alkali and Oxygen

In this work we present a purification technique for oxygen removal from carbon nanotubes (CNTs) at relatively low temperature monitored by X-ray Photoelectron Spectroscopy and electrical characterization (change in resistance). We dope the sample with alkali metal (Na, K and Cs), which successively bind with the residual impurities of oxygen. The removal of the so formed oxides occur by heating the sample at relatively low temperatures (500-600 degrees C) without collateral damage to CNTs mat. In particular we investigate the in situ intercalation of alkali in SWNT followed by oxygen adsorption monitored by DC resistance measurements and X-ray photo-spectroscopy (XPS), demonstrating that the alkali intercalation in the samples trigger the oxygen adsorption. A subsequent sample heating at 500 degrees C removes both oxygen and alkali. Furthermore, the amount of the oxygen removal depends upon the deposited alkali species: in effect only with Na and K we obtain a complete oxygen removal, while other alkalis probably do not intercalate properly inside the nanotube walls. We hypothesize that the atomic radius of alkali can affect the intercalation properties of them inside the CNT structure.

XPS Study of MoO3Interlayer Between Aluminum Electrode and Inkjet-Printed Zinc Tin Oxide for Thin-Film Transistor

In the process of inkjet-printed zinc tin oxide thin-film transistor, the effect of metallic interlayer underneath of source and drain electrode was investigated. The reason for the improved electrical properties with thin molybdenum oxide (MoO3) layer was due to the chemically intermixed state of metallic interlayer, aluminum source and drain, and oxide semiconductor together. The atomic configuration of three Mo 3d 3 and 3d5 doublets, three different Al 2p core levels, two Sn 3d5, and four different types of oxygen O 1s in the interfaces among those layers was confirmed by X-ray photospectroscopy.

Adsorption and Dispersion Characteristics of Superplasticizer with Waste Plexiglas (WPS) on the Surface of Gypsum Particles

A superplasticizer (WPS) was synthesized from waste plexiglas and sodium allysulfonate in this paper. Poly (methyl methacrylate-co-ethyl acrylate) grafling sodium allysulfonate (PMMA-g-AS) was prepared through reactive extrusion in self-single screw extruder and hydrolysis reaction. The structures of the WPS was characterized by FT-IR spectrometer. The results show that structure of the WPS are clear. By using UV-visible adsorption spectrophotometer, micro-electrophoresis potential analyzer, and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. The results indicated that the adsorption behavior of WPS on gypsum particles follows a Langmuir isothermal adsorption model with an adsorption heat of 18.79 kJ/mol and an adsorption layer thickness of 17. 52 nm. Adsorption isotherm suggested that Langmiur single layer adsorption occurred during the process of adsorption of WPS and FDN on gypsum particles.

Adsorption Characteristics of Superplasticizer with Waste Plexiglas (WPS) onto Cement Particle Surface

In this study, by using UV-visible adsorption spectrophotometer, ζ-potential analyzer and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. WPS was prepared through free radical copolymerization in self-Single screw reactive extruder and synthesized from waste plexiglas and vinyl monomers by way of special extrusion modification. The results show that the adsorption of WPS and FDN on cement particle surface approximately conforms to Langmuir’s adsorption isotherm. The adsorption of WPS belongs to physical adsorption and its saturated adsorbed quantity was 5.38mg/g. When the dosage of WPS was 1 wt.% of cement, the thickness of the adsorption layer on the surface of cement particles was 61.2 nm. The ζ-potential of cement particle with WPS changed from positive (15 mV) to negative (-64.74mV) with its concentration increasing from 0 to 20 g/L and decreased from -65.19 to-39.82 mV (reducing by 38.9%) with its concentration of 10 g/L within 60 h.

Fabrication, characterization, and biological assessment of multilayer DNA coatings on sandblasted-dual acid etched titanium surface

As local gene therapy has received attention, immobilizing functional gene onto irregular oral implant surface has become an advanced challenge. Electrostatic layer-by-layer (LBL) assembly technique could achieve this goal and allow local and efficient administration of genes to the target cells. In this study, multilayers of cationic lipid/plasmid DNA (pEGFP-C1) complex (LDc) and anionic hyaluronic acid were assembled onto sandblasted-dual acid etched titanium disks by the LBL technique. Surface characteristics of the coatings were performed by x-ray photospectroscopy (XPS), contact angle measurements, and scanning electron microscopy (SEM). The cell biological characteristics of the coatings were evaluated by in vitro experiments. SEM results demonstrated that the porous titanium surface was gradually flattened with the increase of the multilayer. The XPS survey indicated that the N element was found from the coating. The coating degradation and pEGFP-C1 releasing kinetics showed that the more assembled layer numbers were, the larger the amount of DNA released in the first 30 h. MC3T3-E1 cells were cultured directly on the DNA-loaded surface. Higher enhanced green fluorescent protein (EGFP) expression efficiency was achieved by increasing the number of layers when cells were cultured after 24 or 72 h. The MC3T3-E1 cell viability on the surface of multilayer DNA coatings was significantly higher than that on control porous titanium surface. It was concluded that the approach established by the LBL technique had great potential in immobilizing gene coatings onto the porous titanium surface and subsequently influenced the function of the cultured cell.

Enhanced Photoluminescence and Field-Emission Behavior of Vertically Well Aligned Arrays of In-Doped ZnO Nanowires

Vertically oriented well-aligned Indium doped ZnO nanowires (NWs) have been successfully synthesized on Au-coated Zn substrate by controlled thermal evaporation. The effect of indium dopant on the optical and field-emission properties of these well-aligned ZnO NWs is investigated. The doped NWs are found to be single crystals grown along the c-axis. The composition of the doped NWs is confirmed by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and X-ray photospectroscopy (XPS). The photoluminescence (PL) spectra of doped NWs having a blue-shift in the UV region show a prominent tuning in the optical band gap, without any significant peak relating to intrinsic defects. The turn-on field of the field emission is found to be ∼2.4 V μm(-1) and an emission current density of 1.13 mA cm(-2) under the field of 5.9 V μm(-1). The field enhancement factor β is estimated to be 9490 ± 2, which is much higher than that of any previous report. Furthermore, the doped NWs exhibit good emission current stability with a variation of less than 5% during a 200 s under a field of 5.9 V μm(-1). The superior field emission properties are attributed to the good alignment, high aspect ratio, and better crystallinity of In-doped NWs.

Impact of Pb Doping on the Optical and Electrical Properties of ZnO Nanowires

In this letter, effect of Pb-doping on the electrical and optical properties of the as grown ZnO nanowires (NWs) have been investigated. The microstructural investigations show that the Pb-dopant substituted into wurtzite ZnO nanowires without forming any secondary phase. The amount of contents and valence state of Pb ions has been investigated through energy dispersive spectroscopy and X-ray photospectroscopy. The doped nanowires show a remarkable reduction of 15.3 nm (127.4 meV) in the optical band gap, while an increase amount of deep-level defects transition in visible luminescence. Furthermore, the reduction in the band gap and the presence of deep-level defects induces strong effect in the electrical resistivity of doped NWs, which makes their potential for the fabrication of nanodevices. The possible growth mechanism is also briefly discussed.

Novel polymer nanocomposites based on polystyrene and Ti‐functionalized polyhedral silsesquioxanes

AbstractTi‐based polyhedral silsesquioxanes (Ti‐POSSs) have been prepared and dispersed in polystyrene (PS), by in situ polymerization, and the resulting materials have been characterized by several experimental techniques including both scanning (SEM) and transmission (TEM) electron microscopy, wide angle X‐ray diffraction (WAXD), X‐ray photospectroscopy (XPS), and thermogravimetric analysis (TGA/DTG). TEM and SEM analyses proved that PS nanocomposites of the samples based on heptaisobutyl‐Ti‐POSS (HEI‐Ti‐POSS) are formed, where HEI‐Ti‐POSS cages are directly linked to the macromolecules via Ti‐C bonds. The presence of HEI‐Ti‐POSS enhances the thermo‐oxidative stability of PS‐based nanocomposites and does not significantly affect the polymer molecular mass. Copyright © 2009 John Wiley & Sons, Ltd.

Enhancement and Stabilization of Hole Concentration of Hydrogen-Terminated Diamond Surface Using Ozone Adsorbates

The p-type conductivity of H-terminated diamond surface can be linked to adsorption of a specific gas species on the surface. O3, NO2, NO, and SO2 were identified as adsorbates, which induce holes on the H-terminated diamond surface. Among them, exposure to O3 increases hole concentration the most. The O3-increased concentration remains high even after exposure to the gas has stopped, indicating that ozone is the most stable adsorbent. X-ray photospectroscopy spectra of O3-adsorbed H-terminated diamond surface show partial oxidation of the surface and upward band bending and are very similar to those of NO2 exposed diamond surfaces.

Dominancy of antiferromagnetism in Zn1−x Co x O diluted magnetic semiconductors

The outline of magnetic interactions in DMSs was determined using Zn1−xCoxO particles, where “x” was changed as 0.01, 0.05, 0.10, 0.15, and 0.20. The syntheses were accomplished though mechanical milling and thermal treatment, known as solid state reaction. The formation of each synthesis was monitored by differential thermal and thermo gravimetric methods (DT-TGA). Substitution of Co2+ ions with Zn2+ host atoms in a ZnO lattice was analyzed using X-ray diffraction (XRD) patterns, Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectrometry (EDS) data, transmission electron microscopy (TEM) figures, scanning area electron diffraction (SAED) patterns, and X-ray photo spectroscopy (XPS) spectrum. The measured Co contents in ZnO lattice were found to be ~0.7% less than the expected result. In addition to Zn1−xCoxO particles, tungsten (W) contaminations were noticed in the variations of 1.5 ± 0.2%, as originating from the abrasion between the miller and balls. The progressive replacement of Co2+ with Zn2+ host ions in ZnO lattice from 1% to 20% decreased the band edge from 3.03 ± 0.01 eV to 2.95 ± 0.01 eV, respectively. Co doping has also changed the magnetic nature of the ZnO. Although having both interactions (ferromagnetic and antiferromagnetic), dominance of ferromagnetic behavior was only observed for Zn0.99Co0.01O with the coercivity of ~154 ± 50 Oe and positive Curie–Weiss temperature as 79 ± 1 K. However, the calculated \( {\frac{{2J_{\text{ex}} }}{{k_{\text{B}} }}} \) values have proved that the higher Co2+ concentrations in ZnO lattice have increased the efficiency of antiferromagnetic interactions. Surprisingly, there was no rapid change at \( {\frac{{2J_{\text{ex}} }}{{k_{\text{B}} }}} \) values as mentioned in previous works.

Room-Temperature Ionic Liquid. A New Medium for Material Production and Analyses under Vacuum Conditions

A characteristic of negligible vapor pressure that a room temperature ionic liquid (RTIL) possesses enables us to introduce RTILs in the apparatus requiring vacuum conditions for material productio...

Structural, Optic, and Magnetic Investigation of the Synthesized ZnO and Zn$_{0.99}$Co$_{0.01}$O Semiconductors via Solid State Reaction

Both ZnO and Zn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.99</sub> Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.01</sub> O semiconductors were synthesized through solid state reaction via mechanical milling and thermal treatment. Initially the wurtzite ZnO structures of the synthesized particles were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Since these techniques were unable to identify both contamination atoms and Co distribution, energy dispersive X-ray spectrometry (EDS) was used. EDS showed a successful doping of Co atoms with the atomic ratio of 0.9 ± 0.1%, and also showed a contamination of tungsten (W) atoms, in the atomic ratio of 1.6 ± 0.2% for Zn <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.99</sub> Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.01</sub> O, and 1.3 ± 0.2% for ZnO. Substitutions of Co <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+2</sup> ions with Zn <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+2</sup> host atoms in the ZnO lattice were exposed through X-ray photo spectroscopy (XPS) data of Co 2p electronic energy levels. UV-vis absorption spectroscopy (UV-vis) was also used to prove Co substitutions in the ZnO lattice. This was revealed by a decrease in band gap from 3.25 ± 0.01 eV to 3.03 ± 0.01 eV, and the existence of newly permitted transitions between intra ionic <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> - <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> * levels. The ferromagnetic effect of Co doping in ZnO lattice was revealed by the coercivity of ~154±50 Oe and positive Curie-Weiss temperature, 79 ± 1 K. Beside ferromagnetic interactions, the calculated effective Bohr Magnetron (¿ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</sub> ), 0.32±0.01 ¿ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> , suggested anti-ferromagnetic interactions due to be less than the theoretical spin based magnetic moment of Co <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ions, 3.0 ¿ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> .

Effect of Pb-doping on the morphology, structural and optical properties of ZnO nanowires synthesized via modified thermal evaporation

Pb-doped ZnO nanowires (NWs) have been synthesized by modified thermal evaporation method. Effect of Pb-doping on the morphology, structure, and optical properties of as deposited NWs have been investigated. The TEM images show that the doped NWs consist of cantilever-like with diameter in the range of 20–150 nm. It has been found that the doped NWs are single crystalline grown along [1 0 1] direction. The composition and valence state of Pb ions have been investigated through energy dispersive spectroscopy (EDS) and X-ray photospectroscopy (XPS), which demonstrate that the Pb ions are uniformly doped into each NW and are in +2 oxidation state. In addition, photoluminescence spectra exhibit an increased amount of defects with increasing Pb, which leads to a red shift in the UV region. Furthermore, the band gap tailoring in Pb-doped ZnO NWs makes their potential for optoelectronics devices.