Abstract- Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spect... more Abstract- Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (especially transmission and absorption spectra). The chalcogenide glass of GexSe80-xPb20 has been prepared by melt quenching technique. Thin films of GexSe80-xPb20 are deposited by vacuum thermal evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The transmission spectra in the spectral range 300-2000 nm has been used to calculate the refractive index (n), extinction coefficient (k) of the films have been studied. Optical spectroscopy of the films has been done with the help of the Shimadzu U-3600 (UV-Vis-NIR) Spectrophotometer. The structural analysis is studied through X-ray diffraction.
Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (e... more Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (especially transmission and absorption spectra). The chalcogenide glass of GexSe80-xPb20 has been prepared by melt quenching technique. Thin films of GexSe80-xPb20 are deposited by vacuum thermal evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The transmission spectra in the spectral range 300-2000 nm has been used to calculate the refractive index (n), extinction coefficient (k) of the films have been studied. Optical spectroscopy of the films has been done with the help of the Shimadzu U-3600 (UVVis-NIR) Spectrophotometer. The structural analysis is studied through X-ray diffraction.
The evolution of the structure of Sb8Ge32Se60 (Z 2.72) and Sb20Ge20Se60 (Z 2.60) chalcogenide gla... more The evolution of the structure of Sb8Ge32Se60 (Z 2.72) and Sb20Ge20Se60 (Z 2.60) chalcogenide glasses is determined by high resolution X-ray photoelectron spectroscopy. Glasses with Z 2.60 the structure consists of deformed tetrahedra and pyramids, in which at least one Se atom is substituted by Ge or Sb atom. For the Z 2.72 structure consisting of shared pyramids and tetrahedra with two or more Se atoms substituted by the cations. At the same time, Se-Se dimers are present in both compositions.
Optik - International Journal for Light and Electron Optics, 2016
Abstract Aluminum–nitrogen (Al–N) codoped zinc oxide (ZnO) thin films were grown on glass substra... more Abstract Aluminum–nitrogen (Al–N) codoped zinc oxide (ZnO) thin films were grown on glass substrate by radio frequency (RF) reactive magnetron sputtering using aluminum doped zinc oxide (AZO, 2.5 wt% Al 2 O 3 ) target and N 2 as reactive gas. The structural, morphology, optical and electrical properties were also investigated with different flow rate of N 2 gas. X-ray diffraction results shows that codoped ZnO thin films have similar wurtzite structure like undoped ZnO film. Al–N thin films have high transparency 78% in visible region as the nitrogen flow rate increases the transparency and band gap decreases. The best p-type codoped sample shows a resistivity and hole concentration of 0.554 Ω cm and 8.3 × 10 19 cm −3 at room temperature, respectively. Current–voltage ( I – V ) characteristics of p-type codoped ZnO thin films are also discussed.
Abstract Mn-doped NiO (NiO:Mn) nanopowders were synthesized from an inexpensive sol-gel method. T... more Abstract Mn-doped NiO (NiO:Mn) nanopowders were synthesized from an inexpensive sol-gel method. The XRD peak profile analysis of NiO:Mn nanopowders confirmed the cubic structure. The spherical nanoparticles of NiO:Mn were evaluated from the SEM and TEM analysis and the grain size decreased as the Mn concentration increased. The average crystallite size decreased from 35.44 nm to 30.5 nm and the bandgap increased from 3.79 eV to 3.95 eV as the Mn concentration increased from 0 wt.% to 4 wt.%. The photocatalytic properties of NiO:Mn nanopowders were measured for the lowest and highest Mn dopant concentrations (Mn: 0 & 4 wt.%) by using the methylene blue dye under UV illumination. The NiO:Mn (Mn: 4 wt.%) nanoparticles showed the highest photocatalytic activity due to the highest activation sites. Therefore, it is revealed that the Mn: 4 wt.% nanoparticles are observed to be more suitable for the photocatalytic activity of methylene blue dye degradation.
Abstract Ternary alloyed and tunable band CdS1−xSex quantum dots (QDs) were prepared via successi... more Abstract Ternary alloyed and tunable band CdS1−xSex quantum dots (QDs) were prepared via successive ionic layer absorption and reaction (SILAR) method. The as-prepared photoanodes at different concentrations were characterized for structural, surface morphological, optical and electrical analysis. The result indicated that the photoresponse region and energy band of prepared CdS1−xSexQDs could be varied by controlling the ratios of S and Se. An aqueous solution of polysulfide electrolyte acted as redox mediator. The QDs size were varied from 10.14 nm to 3.362 nm confirms the quantum confinement effect. The highest and lowest photo conversion efficiency (η) of TiO2/ZnS/CdS1−xSex/ZnS quantum dots-sensitized solar cells (QDSSCs) using CuS counter electrode was obtained 5.12% and 3.43%, respectively. Developing the ZnS layer between the TiO2/QDs and at the interface of QD/electrolyte helps to suppress the charge recombination rate and provide the potential barrier between QDs and electrolyte.The photoconversion efficiency was evaluated by using a solar simulator under illumination with an AM 1.5 G spectrum having light intensity of 100 mWcm−2. These results are encouraging and reveals that tunable energy band QDs controlled by the ratio of atoms can contribute an effective approach for developing the higher efficiency of QDSSCs.
Abstract In the present work, different photoanodes, namely ZnO/TiO2 and bare TiO2 were deposited... more Abstract In the present work, different photoanodes, namely ZnO/TiO2 and bare TiO2 were deposited on fluorine-doped tin oxide (FTO) conductive glass substrate by the doctor blade method. CdS quantum dot was deposited on the photoanode by using the successive ionic layer adsorption and reaction (SILAR) method. In this, CuS was also coated on the FTO substrate which acts as the counter electrode. The structural, optical and electrical properties of deposited photoanodes and counter electrode were successfully investigated. The J-V characteristic and the other parameters of quantum dot sensitized solar cell (QDSSC) were analyzed by a using solar simulator under the illumination of a xenon short arc lamp an AM 1.5 G spectrum, having the light intensity of 100 mWcm−2. The power conversion efficiency of QDSSC using different photoanodes were compared. Due to the formation of energy barrier, ZnO/TiO2 using CdS QDs have higher efficiency ( 1.73%) as compared to bare TiO2 using CdS QDs ( 1.01%). It was found that ZnO/TiO2 based QDSSC exhibits 71% higher efficiency than that of TiO2 based QDSSC. The incident photon-to-current conversion efficiency (IPCE) obtained for ZnO/TiO2 electrode were approximately 46% (at 465 nm) and for bare TiO2 electrode around 34% (at 446 nm). The overall investigation supports the electron transport and enhanced performance of the ZnO/TiO2/CdS solar cell.
Abstract The persistent organic pollutants predominantly phenolic compounds and organic dyes are ... more Abstract The persistent organic pollutants predominantly phenolic compounds and organic dyes are the hazardous pollutants into the environment, considered as crucial contaminants in aquatic environment as well and cause to different severe detrimental impact on the human being and other living systems. In the present investigation, hetro-nanostructured Se-ZnO incorporated with different weight % of RGO (0, 1, 3, 5 and 8%) coded as SeZG-0, SeZG-1, SeZG-3, SeZG-5 and SeZG-8 nanocomposites were fabricated using a facile and simple refluxing method for the enhanced photocatalytic degradation and complete mineralization of phenolic compounds (p-Chlorophenol, p-Nitrophenol) and organic dye (methylene blue) via advanced oxidation technique. XRD, Raman, FT-IR, SEM and UV–Vis DRS techniques were used to determine the structural, morphological and optical properties of the synthesized nanocomposites comprehensively, respectively. p-chlorophenol, p-nitrophenol and methylene blue were considered as model organic pollutants in water for the assessment of photocatalytic performance of the SeZG nanocomposites and the mineralization efficiency was obtained 99.02, 98.89 and 99.41% under irradiation of UV light for 105 min, 90 min and 35 min, respectively. The outstanding photocatalytic performance of SeZG nanocomposites revealed by the significant obstruction in the recombination of charge carriers owing to the presence of Se and RGO nanosheets resulting production of additional reactive oxygen species and photodegradation of organic contaminants (p-chlorophenol, p-nitrophenol and methylene) from water. Finally, photodegradation mechanism is proposed.
The widespread existence of different organic contaminants mostly phenolic compounds, organic dye... more The widespread existence of different organic contaminants mostly phenolic compounds, organic dyes and antibiotics in water bodies initiated by the various industrial wastes that raised great scientific concern and public awareness as well recently owing to their prospective capability to spread these contaminants resistant gene and pose hazard to human. In the present study, a series of nanostructured ZnO-CdO incorporated with reduced graphene oxide (ZCG nanocomposites) were successfully synthesized by a simple refluxing method and characterized by using the X-ray diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, photoluminescence spectroscopy, field emission-scanning microscope (FE-SEM) and UV-visible diffused reflectance spectroscopy (DRS) for the photocatalytic degradation of bisphenol A (BPA), thymol blue (ThB) and ciprofloxacin (CFn) with illumination of UV light. The maximum degradation and mineralization of BPA, ThB and CFn was achieved around 98.5%, 98.38% and 99.28% over the ZCG-5 nanocomposite photocatalyst after UV light irradiation for 180 min, 120 min and 75 min, respectively. The superior photocatalytic activity of ZCG-5 ascribed to enhance adsorption capacity, effective separation of charge carriers consequential for the production of more ROS after incorporation of RGO nanosheets with ZnO-CdO in photocatalyst. The conceivable photocatalytic degradation mechanism of BPA, ThB and CFn was elucidated through ROS identification and the assessment of photocatalyst stability by reusability, EEO (kwh/m3order) and UV light dose (mJ/cm2) were evaluated. The plausible photocatalytic degradation pathways were proposed for the degradation of BPA, ThB and CFn via GC-MS analysis. The present work investigates the efficient removal of BPA, ThB and CFn using ZCG nanocomposites as photocatalyst.
Abstract In the present work, the chalcogen (Se2+)-doped ZnO nanoparticles (SeZO-NPs) were synthe... more Abstract In the present work, the chalcogen (Se2+)-doped ZnO nanoparticles (SeZO-NPs) were synthesized using sol-gel precipitation method and tested for photocatalytic degradation of Rhodamine B (RhB). X-ray diffraction pattern of SeZO-NPs showed the hexagonal wurtzite crystal structure regardless of Se concentration. The band edge and defect-level emissions of SeZO-NPs were determined by using the photoluminescence spectra with the excitation source of 370 nm. The bandgap, Eg, of SeZO-NPs was measured from diffused reflectance spectroscopy, which increased from 3.22 to 3.26 eV as Se concentration increased from 0 to 10 wt.%. The highest specific surface area and lowest pore size of 5-SeZO-NPs were observed to be 36.42 m2/g and 13.48 nm, respectively. The photocatalytic degradation of SeZO-NPs was measured under the illumination of ultraviolet (UV) light. The double donor (Se) played an important role toward photodegradation of RhB via reducing the recombination of charge carriers. The highest photocatalytic degradation (98.23%) and mineralization were achieved for the sample 5-SeZO (Se: 5 wt.%). The improved photocatalytic performance of 5-SeZO was attributed to the optimum Se dopant concentration for the production of more reactive oxygen species because of effective separation of charge carriers in UV light.
Abstract In the present work an attempt has been made to improve the stability in the oxygen gas ... more Abstract In the present work an attempt has been made to improve the stability in the oxygen gas sensing property of SnO2 with Sb doping using low cost sol-gel spin coating techniques. Un-doped and Sb (0, 0.5, 1.0, 1.5 and 2 at. %) doped SnO2 thin films were deposited on sodalime glass substrate by spin coating technique at 2500 rpm and annealed at 400 °C. The properties of thin films were investigated by their structural, morphological, optical and electrical analysis for oxygen gas sensing at low operating temperature. The crystalline phase and crystallite size were measured by X-ray diffraction pattern. It was observed that peaks show the polycrystalline nature with the tetragonal crystal structure. Scanning electron microscopic images revealed that all thin films have spherical type morphology. The transmittance spectra were recorded in the wavelength range 200–800 nm and optical band gap was varied from 3.56 eV to 3.92 eV with increasing doping concertation. The I–V measurements were recorded from −5 V to 5 V by two probe method. The highest conductivity was observed for 1 at. % Sb doped SnO2 thin film sample. The gas sensing properties of above thin films were measured as a function of operating temperature in the temperature range from 30 °C to 125 °C and the highest response was obtained for 1 at. % Sb doped SnO2 thin film sample. It has been observed from the experimental results that Sb doped SnO2 thin films exhibit the improved gas response, low operating temperature and good selectivity.
Abstract- Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spect... more Abstract- Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (especially transmission and absorption spectra). The chalcogenide glass of GexSe80-xPb20 has been prepared by melt quenching technique. Thin films of GexSe80-xPb20 are deposited by vacuum thermal evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The transmission spectra in the spectral range 300-2000 nm has been used to calculate the refractive index (n), extinction coefficient (k) of the films have been studied. Optical spectroscopy of the films has been done with the help of the Shimadzu U-3600 (UV-Vis-NIR) Spectrophotometer. The structural analysis is studied through X-ray diffraction.
Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (e... more Vacuum evaporated films of GexSe80-xPb20 have been characterized by using optical spectroscopy (especially transmission and absorption spectra). The chalcogenide glass of GexSe80-xPb20 has been prepared by melt quenching technique. Thin films of GexSe80-xPb20 are deposited by vacuum thermal evaporation technique on highly clean glass substrates and their optical properties such as refractive index (n), extinction coefficient (k), and energy band gap have been studied. The transmission spectra in the spectral range 300-2000 nm has been used to calculate the refractive index (n), extinction coefficient (k) of the films have been studied. Optical spectroscopy of the films has been done with the help of the Shimadzu U-3600 (UVVis-NIR) Spectrophotometer. The structural analysis is studied through X-ray diffraction.
The evolution of the structure of Sb8Ge32Se60 (Z 2.72) and Sb20Ge20Se60 (Z 2.60) chalcogenide gla... more The evolution of the structure of Sb8Ge32Se60 (Z 2.72) and Sb20Ge20Se60 (Z 2.60) chalcogenide glasses is determined by high resolution X-ray photoelectron spectroscopy. Glasses with Z 2.60 the structure consists of deformed tetrahedra and pyramids, in which at least one Se atom is substituted by Ge or Sb atom. For the Z 2.72 structure consisting of shared pyramids and tetrahedra with two or more Se atoms substituted by the cations. At the same time, Se-Se dimers are present in both compositions.
Optik - International Journal for Light and Electron Optics, 2016
Abstract Aluminum–nitrogen (Al–N) codoped zinc oxide (ZnO) thin films were grown on glass substra... more Abstract Aluminum–nitrogen (Al–N) codoped zinc oxide (ZnO) thin films were grown on glass substrate by radio frequency (RF) reactive magnetron sputtering using aluminum doped zinc oxide (AZO, 2.5 wt% Al 2 O 3 ) target and N 2 as reactive gas. The structural, morphology, optical and electrical properties were also investigated with different flow rate of N 2 gas. X-ray diffraction results shows that codoped ZnO thin films have similar wurtzite structure like undoped ZnO film. Al–N thin films have high transparency 78% in visible region as the nitrogen flow rate increases the transparency and band gap decreases. The best p-type codoped sample shows a resistivity and hole concentration of 0.554 Ω cm and 8.3 × 10 19 cm −3 at room temperature, respectively. Current–voltage ( I – V ) characteristics of p-type codoped ZnO thin films are also discussed.
Abstract Mn-doped NiO (NiO:Mn) nanopowders were synthesized from an inexpensive sol-gel method. T... more Abstract Mn-doped NiO (NiO:Mn) nanopowders were synthesized from an inexpensive sol-gel method. The XRD peak profile analysis of NiO:Mn nanopowders confirmed the cubic structure. The spherical nanoparticles of NiO:Mn were evaluated from the SEM and TEM analysis and the grain size decreased as the Mn concentration increased. The average crystallite size decreased from 35.44 nm to 30.5 nm and the bandgap increased from 3.79 eV to 3.95 eV as the Mn concentration increased from 0 wt.% to 4 wt.%. The photocatalytic properties of NiO:Mn nanopowders were measured for the lowest and highest Mn dopant concentrations (Mn: 0 & 4 wt.%) by using the methylene blue dye under UV illumination. The NiO:Mn (Mn: 4 wt.%) nanoparticles showed the highest photocatalytic activity due to the highest activation sites. Therefore, it is revealed that the Mn: 4 wt.% nanoparticles are observed to be more suitable for the photocatalytic activity of methylene blue dye degradation.
Abstract Ternary alloyed and tunable band CdS1−xSex quantum dots (QDs) were prepared via successi... more Abstract Ternary alloyed and tunable band CdS1−xSex quantum dots (QDs) were prepared via successive ionic layer absorption and reaction (SILAR) method. The as-prepared photoanodes at different concentrations were characterized for structural, surface morphological, optical and electrical analysis. The result indicated that the photoresponse region and energy band of prepared CdS1−xSexQDs could be varied by controlling the ratios of S and Se. An aqueous solution of polysulfide electrolyte acted as redox mediator. The QDs size were varied from 10.14 nm to 3.362 nm confirms the quantum confinement effect. The highest and lowest photo conversion efficiency (η) of TiO2/ZnS/CdS1−xSex/ZnS quantum dots-sensitized solar cells (QDSSCs) using CuS counter electrode was obtained 5.12% and 3.43%, respectively. Developing the ZnS layer between the TiO2/QDs and at the interface of QD/electrolyte helps to suppress the charge recombination rate and provide the potential barrier between QDs and electrolyte.The photoconversion efficiency was evaluated by using a solar simulator under illumination with an AM 1.5 G spectrum having light intensity of 100 mWcm−2. These results are encouraging and reveals that tunable energy band QDs controlled by the ratio of atoms can contribute an effective approach for developing the higher efficiency of QDSSCs.
Abstract In the present work, different photoanodes, namely ZnO/TiO2 and bare TiO2 were deposited... more Abstract In the present work, different photoanodes, namely ZnO/TiO2 and bare TiO2 were deposited on fluorine-doped tin oxide (FTO) conductive glass substrate by the doctor blade method. CdS quantum dot was deposited on the photoanode by using the successive ionic layer adsorption and reaction (SILAR) method. In this, CuS was also coated on the FTO substrate which acts as the counter electrode. The structural, optical and electrical properties of deposited photoanodes and counter electrode were successfully investigated. The J-V characteristic and the other parameters of quantum dot sensitized solar cell (QDSSC) were analyzed by a using solar simulator under the illumination of a xenon short arc lamp an AM 1.5 G spectrum, having the light intensity of 100 mWcm−2. The power conversion efficiency of QDSSC using different photoanodes were compared. Due to the formation of energy barrier, ZnO/TiO2 using CdS QDs have higher efficiency ( 1.73%) as compared to bare TiO2 using CdS QDs ( 1.01%). It was found that ZnO/TiO2 based QDSSC exhibits 71% higher efficiency than that of TiO2 based QDSSC. The incident photon-to-current conversion efficiency (IPCE) obtained for ZnO/TiO2 electrode were approximately 46% (at 465 nm) and for bare TiO2 electrode around 34% (at 446 nm). The overall investigation supports the electron transport and enhanced performance of the ZnO/TiO2/CdS solar cell.
Abstract The persistent organic pollutants predominantly phenolic compounds and organic dyes are ... more Abstract The persistent organic pollutants predominantly phenolic compounds and organic dyes are the hazardous pollutants into the environment, considered as crucial contaminants in aquatic environment as well and cause to different severe detrimental impact on the human being and other living systems. In the present investigation, hetro-nanostructured Se-ZnO incorporated with different weight % of RGO (0, 1, 3, 5 and 8%) coded as SeZG-0, SeZG-1, SeZG-3, SeZG-5 and SeZG-8 nanocomposites were fabricated using a facile and simple refluxing method for the enhanced photocatalytic degradation and complete mineralization of phenolic compounds (p-Chlorophenol, p-Nitrophenol) and organic dye (methylene blue) via advanced oxidation technique. XRD, Raman, FT-IR, SEM and UV–Vis DRS techniques were used to determine the structural, morphological and optical properties of the synthesized nanocomposites comprehensively, respectively. p-chlorophenol, p-nitrophenol and methylene blue were considered as model organic pollutants in water for the assessment of photocatalytic performance of the SeZG nanocomposites and the mineralization efficiency was obtained 99.02, 98.89 and 99.41% under irradiation of UV light for 105 min, 90 min and 35 min, respectively. The outstanding photocatalytic performance of SeZG nanocomposites revealed by the significant obstruction in the recombination of charge carriers owing to the presence of Se and RGO nanosheets resulting production of additional reactive oxygen species and photodegradation of organic contaminants (p-chlorophenol, p-nitrophenol and methylene) from water. Finally, photodegradation mechanism is proposed.
The widespread existence of different organic contaminants mostly phenolic compounds, organic dye... more The widespread existence of different organic contaminants mostly phenolic compounds, organic dyes and antibiotics in water bodies initiated by the various industrial wastes that raised great scientific concern and public awareness as well recently owing to their prospective capability to spread these contaminants resistant gene and pose hazard to human. In the present study, a series of nanostructured ZnO-CdO incorporated with reduced graphene oxide (ZCG nanocomposites) were successfully synthesized by a simple refluxing method and characterized by using the X-ray diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy, photoluminescence spectroscopy, field emission-scanning microscope (FE-SEM) and UV-visible diffused reflectance spectroscopy (DRS) for the photocatalytic degradation of bisphenol A (BPA), thymol blue (ThB) and ciprofloxacin (CFn) with illumination of UV light. The maximum degradation and mineralization of BPA, ThB and CFn was achieved around 98.5%, 98.38% and 99.28% over the ZCG-5 nanocomposite photocatalyst after UV light irradiation for 180 min, 120 min and 75 min, respectively. The superior photocatalytic activity of ZCG-5 ascribed to enhance adsorption capacity, effective separation of charge carriers consequential for the production of more ROS after incorporation of RGO nanosheets with ZnO-CdO in photocatalyst. The conceivable photocatalytic degradation mechanism of BPA, ThB and CFn was elucidated through ROS identification and the assessment of photocatalyst stability by reusability, EEO (kwh/m3order) and UV light dose (mJ/cm2) were evaluated. The plausible photocatalytic degradation pathways were proposed for the degradation of BPA, ThB and CFn via GC-MS analysis. The present work investigates the efficient removal of BPA, ThB and CFn using ZCG nanocomposites as photocatalyst.
Abstract In the present work, the chalcogen (Se2+)-doped ZnO nanoparticles (SeZO-NPs) were synthe... more Abstract In the present work, the chalcogen (Se2+)-doped ZnO nanoparticles (SeZO-NPs) were synthesized using sol-gel precipitation method and tested for photocatalytic degradation of Rhodamine B (RhB). X-ray diffraction pattern of SeZO-NPs showed the hexagonal wurtzite crystal structure regardless of Se concentration. The band edge and defect-level emissions of SeZO-NPs were determined by using the photoluminescence spectra with the excitation source of 370 nm. The bandgap, Eg, of SeZO-NPs was measured from diffused reflectance spectroscopy, which increased from 3.22 to 3.26 eV as Se concentration increased from 0 to 10 wt.%. The highest specific surface area and lowest pore size of 5-SeZO-NPs were observed to be 36.42 m2/g and 13.48 nm, respectively. The photocatalytic degradation of SeZO-NPs was measured under the illumination of ultraviolet (UV) light. The double donor (Se) played an important role toward photodegradation of RhB via reducing the recombination of charge carriers. The highest photocatalytic degradation (98.23%) and mineralization were achieved for the sample 5-SeZO (Se: 5 wt.%). The improved photocatalytic performance of 5-SeZO was attributed to the optimum Se dopant concentration for the production of more reactive oxygen species because of effective separation of charge carriers in UV light.
Abstract In the present work an attempt has been made to improve the stability in the oxygen gas ... more Abstract In the present work an attempt has been made to improve the stability in the oxygen gas sensing property of SnO2 with Sb doping using low cost sol-gel spin coating techniques. Un-doped and Sb (0, 0.5, 1.0, 1.5 and 2 at. %) doped SnO2 thin films were deposited on sodalime glass substrate by spin coating technique at 2500 rpm and annealed at 400 °C. The properties of thin films were investigated by their structural, morphological, optical and electrical analysis for oxygen gas sensing at low operating temperature. The crystalline phase and crystallite size were measured by X-ray diffraction pattern. It was observed that peaks show the polycrystalline nature with the tetragonal crystal structure. Scanning electron microscopic images revealed that all thin films have spherical type morphology. The transmittance spectra were recorded in the wavelength range 200–800 nm and optical band gap was varied from 3.56 eV to 3.92 eV with increasing doping concertation. The I–V measurements were recorded from −5 V to 5 V by two probe method. The highest conductivity was observed for 1 at. % Sb doped SnO2 thin film sample. The gas sensing properties of above thin films were measured as a function of operating temperature in the temperature range from 30 °C to 125 °C and the highest response was obtained for 1 at. % Sb doped SnO2 thin film sample. It has been observed from the experimental results that Sb doped SnO2 thin films exhibit the improved gas response, low operating temperature and good selectivity.
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Papers by L.P. Purohit