Quaternary semiconductor (CdZnS):Sn films with five different molar percentages of tin (1–5

This work deals with the synthesization of pristine and Fe-doped CdS nanocrystalline thin films by the sol-gel spin coating method with the freshly prepared solution (Set-A) and 24 h aged solution (Set-B). The XRD patterns of pristine and Fe-doped nanocrystalline CdS thin films (Set-A) reveal hexagonal structure and the other films of set-B exhibit cubic structure. The average crystallite size of all pristine and Fe-doped nanocrystalline CdS thin films (Set-A and Set-B) was found to be lying in the range of 4.997-17.142 nm. The particle size calculated from TEM studies was found to be 11.14 nm, 10.74 nm and 8.74 nm for pristine, 2 ml Fe doped, and 5 ml Fe doped CdS thin films. The average surface roughness of the films was found to be 0.1518 nm, 4.2216 nm, and 0.1471 nm for Fe_00, Fe_01, and Fe_05 samples of Set-A, while it was found to be 0.2055 nm, 4.839 nm and 0.1803 nm for Fe_00, Fe_01 and Fe_05 samples of Set-B respectively. PL spectra reveal the occurrence of cyan emission for both sets of samples. The band gap values for the nanocrystalline thin films (Set-A) were 2.46-2.71 eV and for Set-B were in the range of 2.47-2.75 eV, which is higher than that of bulk CdS (2.42 eV). The low-temperature resistivity of the deposited films of both sets was obtained in the range of 105 to 103 omega cm, and also found to decrease with increasing Fe concentration in CdS.

In the current study, pristine and Co@CdS nanocrystalline thin films were fabricated on glass substrates by sol–gel spin coating technique. The structural and optical properties of fabricated films were systematically evaluated. The fabricated films are polycrystalline in nature and have a cubic structure. An investigation of the structure reveals that Co ions have been fully integrated into the CdS lattice. Crystallite size, microstrain, and lattice parameters were calculated using the Debye–Scherrer formula. The crystallite size of the pristine CdS thin films was observed to be 12.05 nm and decreased to 9.73 nm with Co-doping. Also, the microstrain and dislocation density of the films increased with an increase in Co-doping concentration. The 1-LO and 2-LO Raman peaks were found to be shifted toward the lower frequency side. Transmittance, refractive index, and extinction coefficient were examined to identify the changes in optical characteristics caused by Co-doping. The doping process improves the energy bandgap of the CdS nanocrystalline thin film which was in the range of 2.46 to 2.56 eV. The doping also alters the photoluminescence characteristics of CdS, leading to a change in peak toward shorter wavelengths for Co@CdS. The RMS roughness and average grain size of the films decreased with doping. These findings suggest that synthesized films could be a potential material used for optoelectronic applications.

In this work, good quality nanocrystalline cadmium sulphide (CdS) thin films were deposited on the suitably cleaned glass slides with different Cu-doping concentrations using the sol–gel spin-coating technique. The effect of Cu doping on the structural, Raman spectra, optical, electrical, photoluminescence, and photoconductivity properties of the fabricated films was studied. The structural properties of the films were investigated using XRD spectra. The X-ray diffraction results indicated that the crystallite size of Cu-doped nanocrystalline CdS thin films was smaller than that of undoped CdS and the cubic zinc blende structure of the films was observed. Raman scattering was utilized to investigate the optical properties of nanocrystalline CdS thin films and reveal the existence of two main peaks 303 and 604 cm−1 which are very close to the standard LO frequency. The optical characterization of the films was carried out from optical transmittance and absorption obtained by a double-beam spectrophotometer in the wavelength range from 400 to 800 nm. UV–visible spectroscopy depicts the enhancement of the optical band gap of Cu-doped nanocrystalline CdS thin films compared to the bulk CdS, as a result of the quantum confinement effect. Photoluminescence spectra of the films reveal the occurrence of blue band emission and an increase in emission intensity with Cu-doping concentration. The change of the electrical resistivity and conductivity of the deposited films with temperature was also investigated. A decrease in resistivity and increase in electrical conductivity was detected as increasing Cu-doping in CdS. The dark and photocurrents and photosensitivity of the films were found to be increased linearly with increasing voltage and doping concentration.

Thin films of Sb-doped CdSe have been deposited on glass substrates by a chemical method at room temperature. The X-ray diffraction pattern confirms the presence of a cubic phase with preferred orientation along the (111) plane. The elemental composition of the thin films has been examined utilizing energy dispersive X-ray analysis. Morphology of the thin films has been investigated using scanning electron microscopy. In the optical absorption study, a decrease in the band gap with increase in Sb doping in CdSe lattice has been observed. Photoluminescence spectra show a redshift in the emission peak with an increase in Sb doping in CdSe. Electrical resistivity measurements are additionally carried out utilizing a two-probe DC method, and two types of conduction mechanisms are observed. Raman analysis shows the formation of CdSe thin films with a nanocrystalline phase. Contact angle measurement establishes the hydrophilic behavior of Sb-doped CdSe thin films with water.

In the present work, we have successfully fabricated undoped and Ni-doped nanocrystalline CdS thin film on an ultrasonically cleaned glass substrate employing the sol–gel spin coating technique. The structural and spectroscopic properties of the films were investigated using XRD spectra, UV–Vis spectroscopy and photoluminescence spectra, respectively. The X-ray diffraction spectra revealed the polycrystalline nature of films with cubic structure and (111) as preferred orientation. The average crystallite size evaluated by the Debye–Scherrer formula lying in the range of 6–12 nm for the deposited films. According to UV–VIS Spectroscopy, the average transmittance of films in the visible region varies between 70–90%. The optical band gap of CdS thin film was evaluated from absorption spectra. The bandgap of the deposited films is in the range of 2.48–2.70 eV which is higher than that of bulk CdS (2.42 eV). This verifies the blue shifting in band edge of CdS nanocrystalline thin films due to the quantum confinement effect. Photoluminescence spectra of the thin film showed that the fundamental band edge emission peak centred at 485 nm also called blue band emission. It is observed that the low temperature resistivity of the films was in the range of 10 7 –10 3 Ω cm and also found to decrease with increasing Ni concentration, as a result from dc two probe measurements.

Doping is a prevalent technique for improving the optoelectronic properties of semiconductor thin films. Bismuth (Bi) doped nanocrystalline cadmium selenide thin films deposited on glass substrates were prepared by a chemical deposition method. The effect of different doping percentages of Bi has been investigated in detail. X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy, energy dispersive x-ray analysis, electrical techniques, optical absorption, photoluminescence, Raman spectroscopy, and water wettability measurement were used to characterize the films. X-ray diffraction showed the formation of a polycrystalline CdSe cubic phase with the preferential orientation (111). The optical band gap values decreased as the Bi doping concentration increased. The high optical band gap of the films up to 2.62 eV showed a strong blue shift. Films were luminescent with emission in the green region when they were excited with a UV source. The resistivity of the thin films was found to decrease with increase in Bi concentration. Surface morphology showed an almost uniform distribution of spherical grains. Water wettability analysis showed that the films were purely hydrophilic. Raman analysis confirmed the formation of nanocrystalline CdSe thin films.

Nanostructured CdS (nCdS) and ternary SnxCd1−xS thin films capped with thioglycerol and methanol in 1:1 ratio in aqueous medium were prepared using hydrated stannous chloride (SnCl2·2H2O), anhydrous cadmium acetate (CH3COO)Cd·2H2O and thiourea (CS(NH2)2) as sources of Sn, Cd and S ions, respectively. Thickness of the film drastically decreases for low concentrations (0–2%) of Sn doping, then increases for (2–3%) and 5% Sn doping. Effects of Sn concentration variation on the optical properties, photoluminescence and structural properties of the nanoparticles were studied. The optical transmittance measurement using ultraviolet–visible–near infrared spectroscopy showed more than 80% transparency in the wavelength range 450–800 nm for 3% and 5% Sn doping. The direct optical band gap value of nanoCdS thin films was obtained as 2.91 eV, which decreased with Sn doping for its varying concentrations. Photoconductivity gain was negligible. A decrease in intensity of lower wavelength emission at 430 nm in nCdS was observed to have (2–5)% Sn content. X-ray diffraction patterns and selected area electron diffraction patterns confirmed formation of the nanocrystalline hexagonal CdSnS phase. Scanning electron microscope and transmission electron microscope measurements of the CdSnS thin films show that the particle size lies well under 20 nm.

Tin-doped nanocrystalline CdSe thin films were deposited onto glass substrate by simple chemical bath deposition technique. The films obtained were uniform and had good adherence to the substrate. The influence of Sn (0–5%) doping on the optical, photoluminescence, electrical, morphological, compositional and structural properties of the films was investigated. The optical absorption studies revealed that the optical band gap of the films varied from 2.62 eV for nano CdSe to 2.50 eV for 5% Sn:CdSe. These films are appropriate for application in different optoelectronics devices due to band gap tunability property. To analyze photoluminescence properties, the films were excited by UV (235 nm) and almost green spectrum was emitted by the films. It is observed that the low temperature resistivity of the thin films was in the range 107–104 Ω cm and also found to decrease with Sn concentration, as resulted from the dc two probe measurements. Activation energy was also calculated. Noticeable changes were observed in the optical and electrical properties of CdSe thin films due to the presence of Sn dopant. Surface morphology study using TEM/SEM showed almost uniform distribution of spherical grains. The elemental composition study using energy dispersive spectroscopy (EDAX) confirms the existence of the desired elements. X-ray diffraction pattern indicated that the formed structure is cubic with most prominent peak at (111). Some important structural parameters such as lattice constant, crystallite size, strain, dislocation density and number of crystallites per unit area were calculated and presented.

Phosphors used are mostly rare earth doped complex structures. A simple and unique material system of CdSe:Mg nanocrystalline thin films, which efficiently absorb UV (235 nm) and emit broad spectrum of green-yellow region has been prepared by chemical bath deposition method with average particle size of 52.3 nm, measured using AFM images. The optical absorption studies found that CdSe thin film has direct optical band gap, \({E_g}\) of 2.62 eV that shows a blue shift of 0.88 eV compared to the bulk \({E_g}\) value. Optical, electrical, structural and morphological properties were studied by UV–Vis–NIR spectrophotometer, photoluminescence (PL) emission spectra, dc two-probe method, X-ray diffraction (XRD), and atomic force microscope (AFM). Measured electrical resistivity decreased with increase of doping concentration. Activation energy was also calculated. The results confirm that the CdSe:Mg thin films are in the pure cubic phase. The magnesium concentrations also affect the nanocrystalline nature of the CdSe thin films. The optical band gap and surface roughness of CdSe thin films mostly decrease with 5% doping of Mg. The effect of Mg doping on refractive index, extinction coefficient and other optical parameters was also investigated.

Our goal in this research was to obtain pure and zinc doped lead oxide nanostructure through chemical root method. 0.04M aqueous solution of lead nitrate and zinc chloride was mixed with 0.08M aqueous solution of sodium hydroxide for making reaction solution. 0.001M aqueous solution of TEA ((Tri Ethanol Amine) was also added to reaction solution. The prepared pure and Zn doped lead oxide nanostructure was characterized by Fourier transformation infrared spectroscopy(FTIR), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM) and high resolution-transmission electron microscopy (HRTEM) and selected area electron diffraction pattern (SAED) pattern reveals the crystalline nature of the sample. The prepared pure and doped lead oxide consists of the average crystallites about 12 and 5nm respectively. Optical band gap of pure and doped lead oxide sample are 5.17 and 5.5eV obtained respectively. The photoluminescence (PL) spectra were investigated for both the sample. The PL spectrum shows peaks in UV region at 356nm, blue regions around 421nm and in green region around 544nm. The spectra show a strong emission band around 421nm.

The present paper reports the synthesis and structural characterization of lead oxide. The sample was prepared by Chemical route method using TEA as capping agent. The particle size of prepared sample was calculated by XRD technique and Confirmed by Scanning electron microscope. The average crystal size of the lead oxide was15-20nm range

In this research our aim was to obtain pure and Zn doped lead hydroxide nanostructure by chemical root method. For making reaction solution we used 0.04M aqueous solution of lead nitrate and zinc chloride was mixed with 0.08M aqueous solution of sodium hydroxide 0.001M aqueous solution of TEA (Tri Ethanol Amine) was also added to reaction solution. Powder was annealed at 190°C. The prepared pure and Zn doped lead oxide nanostructure was characterized, X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution-transmission electron microscopy (TEM) and photo luminescence of the sample. The prepared pure and doped lead hydroxide consists of the average crystallites about 20 and 12nm and band gap obtained 4.93 and 5.25eV respectively. The pure lead oxide phosphor material shows a broad peak at 501nm (near to Green region) and Zn doped lead oxide show the peak at lower wavelength side 402nm (blue region).

Zinc oxide thin films were deposited on glass slide from aqueous solution of ZnCl2 and NaOH by chemical bath deposition method. The films of various thicknesses have been obtained by varying the concentration of TEA (1 M−0.01 M). Optical properties, surface morphology and particle size of the deposited thin film have been studied by U.V spectrophotometer (Varian) SEM and XRD. The optical band gap of the ZnO thin film was found in the range of 2.59–3.57 ev. Optical constant is such as refractive index, extinction coefficient, real and imaginary parts of dielectric constant were evaluated from reflectance, transmittance and absorbance curve. The film show high transmittance in the visible/near infrared region. Reflectance (10%–20%), refractive index (2–2.6), extinction coefficient (0.04–0.075), real (4–7) and imaginary parts (0.2–.0.3) of dielectric constant are obtained in visible/near infrared region. SEM studies shown plate and powder like morphology of sample. Particles size is obtained in nano range.

We report the synthesis and optical properties of ZnO nano particle using TEA (Tri Ethanol Amine) and without TEA by chemical route method. By decreasing the concentration of TEA, reaction rate is decreases and inter planner spacing d is increases, band gap is increased from 4.1 to 4.8 eV. In case of without TEA band gap is obtained 3.4 eV. Morphology, growth and the nature of crystalline of the powder samples were performed by X- ray Diffraction (XRD); UV spectrophotometer, scanning electron microscope (SEM) and Photoluminescence (PL). Luminescence properties are discussed by probing the photoluminescence properties of ZnO nano particles with TEA at different molar concentrations. (C) 2015 Elsevier Ltd. All rights reserved.

Different sized (micro to nano) crystals of lead hydroxide were obtained by using decreasing molar concentrations of TEA (Tri Ethanol Amine) 1–0.01M to the growing reaction solution by a chemical route method. Color of the samples turned white from light yellow after adding TEA. The experimental results indicate successful growth of lead hydroxide in solid form. This was rarely observed ever before. Further powder samples were annealed at 80°C. The elemental composition and the surface morphology were studied using energy dispersive and Field Emission Scanning Electron Microscopy. Transmission Electron Microscopy along with SADE pattern reveals the crystalline nature of the sample. X-ray diffraction patterns of the crystals were obtained which confirm the crystals structure of the lead hydroxide. Band gap varies from 3.28 to 4.51eV.

•We deposited Sb doped nanocrystalline PbS thin films by chemical bath deposition technique.•We examined the effect of Sb doping and annealing on the physical properties of the films.•The crystallite size of the films increased with increasing doping concentration of Sb in PbS.•The absorption edge shifted towards lower wavelength region due to quantum confinement.•Electrical resistivity of the films was 1.29–3.7×106Ωcm.

Nanocrystalline (Pb 1-x Bi x )S thin films were successfully deposited on suitably cleaned glass substrate at constant room temperature, using the chemical bath deposition technique. After deposition the films were also annealed at 400 0 C for 1 hour in air. The crystal structures of the films were determined by X-ray diffraction studies. The films are adherent to the substrate and well crystallized according to cubic structure with the preferential orientation (200). The crystallite size of the pure PbS thin films at optimized deposition time 30 min was found to be 40.4 nm, which increased with Bi content in pure nanocrystalline PbS thin films. The surface roughness of the films was measured by AFM studies. Experiments showed that the growth parameters, doping and annealing influenced the crystal structure of the films. Key word : A. Thin films, B. Chemical synthesis C. Atomic force microscopy, D. X-ray diffraction Corresponding author. Tel: +91 788 2323997; Fax: +91 788 2210163 Email address: rajeshlalwani12003@yahoo.co.in

(Cd1-xSbx)S thin films were deposited onto glass substrates by the chemical bath deposition. Systematic studies have been undertaken to investigate the effect of Sb composition on thin film properties of chemically deposited (Cd1-xSbx)S thin films. The films were characterized by using X-ray diffractometer (XRD), atomic force microscopy (AFM), photoluminescence emission spectra and UV-VIS-NIR spectrophotometer. The XRD patterns reveal that these thin films have mixed phase of cubic CdS and orthorhombic Sb2S3 crystal structure. AFM images showed uniform deposition of the material over the entire glass substrate and rms roughness was also calculated. The energy band gap for thin films were revealed from the optical studies and were found to decrease from 2.41 eV to 2.20 eV with increasing Sb doping concentration. After annealing at 400 degrees C, the band gap is found to be increased in the range 2.51-2.26 eV. The photoluminescence emission spectra of the films shows two luminescence bands centered around 420 nm and 510 nm under 250 nm excitation. (C) 2013 Elsevier Ltd. All rights reserved.

In this paper, nanocrystalline (Pb1-xBix)S thin films were successfully deposited on suitably cleaned glass substrate at constant room temperature, using the chemical bath deposition technique. The deposited films were further annealed at 400 0 C in air. The optical characterization of the films was done by optical absorption and transmission spectra in the range 400-1100 nm using UV spectrophotometer. The band gap of the films was found to be in the range 1.6-2.2 eV for x = 0 to 0.05. The room temperature electrical resistivity of the synthesized films was measured by photoconductivity measurement unit. On increasing Bi doping concentration, electrical conductivity decreases.