Nebulizer Spray Pyrolysis Technique Research Articles

Boosting the UV photo-detecting properties of V2O5 thin films by doping In3+ doping

In recent years, optoelectronic technology has demanded the development of efficient photodetectors by layered semiconductor materials at affordable prices. Herein, we put the efforts to generate V2O5 thin films on the surface of glass slides with diverse insertion of In content (0, 1, 2, 3, 4, and 5 wt%) via cost effective nebulizer spray pyrolysis technique and examined their application in U.V. photosensing. Standard characterization techniques are used for these films to identify the cause of In dopant on its morphological, structural, and opto-electrical properties. X-ray diffraction (XRD) plots confirm the development of single-phase orthorhombic structure grown along [010] direction, without the appearance of foreign phases. Further, the dopant ingredient (In) hikes the crystallinity and crystallite sizes (36–51 nm) up to a certain threshold level (2 wt%) and decreases it for further growing In doping. The Field emission scanning electron microscope (FESEM) images display homogeneous nanorods morphology formation at all doping levels. Doping improved its photon absorption in the U.V. region, and the bandgap obtained from the absorbance spectra tuned to a lower value of 1.98 eV up to 2 wt%. All the created thin films emit intense emission bands at 475 nm and 640 nm. Characterization involving I-V measurements under 365 nm illumination at 5 V bias exhibiting commendable performance in terms of photodetector metrics (Responsivity (R) = 7.96 × 10−1 AW−1, Detectivity (D*)=3.63 × 1011 Jones and External quantum efficiency (EQE) = 186 %) for 2 % In doped V2O5. The same sample exhibits a fast-rising /falling time up to 0.6s /0.7 s, respectively. Our results may widen the field of applications in high-performance U.V. photodetector.

Influence of Sn doping on particle cluster to rock-plate growth of nano-structured In2S3 thin films by nebulized spray pyrolysis technique

ABSTRACT The Nebulized Spray Pyrolysis (NSP) process has created Sn-doped In2S3 thin films for various molar percentages on micro glass substrates. The structural, optical, morphological, and electrical characteristics of the thin films have all been studied. A cubic phase had formed in each of the deposited films, according to an X-ray diffraction analysis. The average transmittance of the films ranged from 75 to 96%, while the bandgap energies for direct permitted transitions varied from 2.32 to 2.77 eV. The Scanning Electron Microscopy (SEM) images showed the rock-plate type nanoparticles grown over the surface of the glass plates. The Hall effect study revealed the n-type conductivity and with a 3 mol% Sn-doped In2S3 thin film exhibited a carrier concentration of 17.36 × 1018 cm−3 with the lowest resistance of 21.6 Ω-cm.

Nanostructured Oxide (SnO2, FTO) Thin Films for Energy Harvesting: A Significant Increase in Thermoelectric Power at Low Temperature.

Previous studies have shown that undoped and doped SnO2 thin films have better optical and electrical properties. This study aims to investigate the thermoelectric properties of two distinct semiconducting oxide thin films, namely SnO2 and F-doped SnO2 (FTO), by the nebulizer spray pyrolysis technique. An X-ray diffraction study reveals that the synthesized films exhibit a tetragonal structure with the (200) preferred orientation. The film structural quality increases from SnO2 to FTO due to the substitution of F- ions into the host lattice. The film thickness increases from 530 nm for SnO2 to 650 nm for FTO films. Room-temperature electrical resistivity decreases from (8.96 ± 0.02) × 10-2 Ω·cm to (4.64 ± 0.01) × 10-3 Ω·cm for the SnO2 and FTO thin films, respectively. This is due to the increase in the carrier density of the films, (2.92 ± 0.02) × 1019 cm-3 (SnO2) and (1.63 ± 0.03) × 1020 cm-3 (FTO), caused by anionic substitution. It is confirmed that varying the temperature (K) enhances the electron transport properties. The obtained Seebeck coefficient (S) increases as the temperature is increased, up to 360 K. The synthesized films exhibit the S value of -234 ± 3 μV/K (SnO2) and -204 ± 3 μV/K (FTO) at 360 K. The estimated power factor (PF) drastically increases from ~70 (μW/m·K2) to ~900 (μW/m·K2) for the SnO2 and FTO film, respectively.

Proliferation in the photo-response characteristics of MDC thin films for optoelectronic applications through NSP technique

Nebulizer spray pyrolysis (NSP), a simple thin-film deposition method, was used to fabricate p-Si/n-manganese-doped cerium oxide (MDC)/Al photodiodes. The structure, morphology, optics, composition, electrical and rectifying properties of the prepared materials were analyzed. UV-Vis analysis demonstrates a prominent and acute absorption edge at 425 nm in the visible region. As more Mn impurities are incorporated into CeO2 crystallites, the band gap decreases as the doping level increases, leading to the formation of new recombination sites with low energy emissions. Electrons in outer orbits operate in energy bands, moving to higher energy levels. At higher Mn doping, some NBE emissions and green emission peaks disappear. The emission spectrum confirmed that strong and broad blue emission peak occurred for the diode containing the 15% Manganese Diode Cerium film. XRD peak shows the mono-phase polycrystalline cubic fluorite structure with the main orientation in the 200 directions. The broad lines (CeO) symmetry at 695,659,538 and 517 cm−1 observed in the Fourier Transform -Infrared spectrum are due to the phonons of the cerium oxide (Ce-O) network caused by asymmetric tip stretching and fastening vibration. Satellite peaks arise due to the transition from ligand (O 2p) to metal (Ce 4f) achieved during the primary and main photo-ionization process. This suggests that the valence states of Ce3+ and Ce4+ provide access to the CeO2 lattice sites. The I-V properties of p-Si/n-MDC/Al devices show behavior limited by the properties of the inorganic semiconductor substrate and the size of the hetero-interface energy barrier. The switching voltage of the hetero-junction was found to be approximately 2.4 V.

Study of rectifying properties and true Ohmic contact on Sn doped V2O5 thin films deposited by spray pyrolysis method

In this paper, V2O5 thin-films were deposited on glass substrates by using the ultrasonically nebulized spray pyrolysis technique. Doping concentration of 1 %, 2 %, and 7 % of Sn, in V2O5 thin-films is studied by using metal–semiconductor-metal (MSM) based device structure. X-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM) were used to analyze the surface morphology of the thin films. The XRD spectroscopic analysis shows the crystal size of above-mentioned samples, to be respectively 39 nm, 58 nm, 60 nm and 72 nm. The FESEM images showed the enhancement of crystal size with increase in Sn doping concentration. The optical properties of Sn doping on V2O5 thin film were studied by using UV–Vis spectrometer. The UV–Vis spectroscopic analysis shows that the absorption coefficient values decrease with increase in concentration of Sn metal doping in V2O5 thin film. The activation energies of all thin-film samples were calculated from Arrhenius plots and were found to be 0.938 eV, 1.101 eV, 1.11 eV and 1.169 eV, respectively, for all the thin-film samples mentioned above. The MSM based structure was fabricated by using a shadow mask and thermal evaporation. Later, the I-V characteristics of all the thin films were obtained by using semiconductor parameter analyzed at a biased voltage between −50 V and + 50 V with a step size of 1 V. Rectification ratio of the V2O5 films is significantly enhanced as the doping concentration increases. It was found that the rectification ratio of undoped V2O5 thin films increased linearly from 1.018 to 1.059 with an increase in temperature from room temperature to 130 °C. Similar trend was followed for 1 % (from 1.079 to 1.198), 2 % (from 1.081 to 1.224) and 7 % (from 1.095 to 1.311) Sn doped films. These results show the potential application of V2O5 thin films in the field of optoelectronics and thin film gas sensors.

Effect of Manganese Doping in SnO2 Thin Films and its NO2 Gas Sensing Performance

By using an automated nebulizer spray pyrolysis technique with varied concentrations of manganese chloride (0 - 3%) in the spray solution of tin chloride, thin films of pure and manganese-doped tin oxides (Mn-SnO2) were deposited. X-ray diffraction investigations indicated that 2% Manganese chloride concentration in the spray solution promoted development along (200) and (220) directions. The preferred growth direction in the (200) and (220) planes decreased with increasing manganese chloride doping concentration (2-3%) in the solution. The surface morphology of the films had changed as a result of adding Manganese as a dopant. Compositional analysis was carried out using EDAX. From UV-Vis spectroscopy, the optical properties of the SnO2 and Mn-SnO2 thin film were observed; the maximum optical absorbance was in the wavelength range of 300 - 400 nm. The concentration of Mn in the films affected the intensity of the photoluminescence emission peak detected at 347 and 392 nm for pure SnO2 and Mn-SnO2 films, respectively. The gas sensing performance of the films was examined by dynamic method against NO2 gas, at an operating temperature of 250 °C and 400 ppm gas concentration. Mn-SnO2 films achieved quick response and recovery times of 17 s and 34 s.

Synthesis and enhanced room temperature ammonia gas–sensing properties of In-doped MoO3 thin films prepared via nebulizer spray pyrolysis technique

Synthesis and enhanced room temperature ammonia gas–sensing properties of In-doped MoO3 thin films prepared via nebulizer spray pyrolysis technique

Nebulizer spray pyrolysis Sm3+ doped TiO2 thin film characteristics and room temperature gas sensing

In this work, pure TiO2 and Samarium doped (1, 3, 5 wt%) TiO2 thin films was successfully deposited on the FTO substrate by Nebulizer spray pyrolysis technique. The result suggested prepared TiO2 film have tetragonal structure and an anatase phase along the (101) direction. According to the UV–Vis-NIR spectroscopic analysis, all the deposited films exhibited a high optical percentage of transmittance, surpassing 80 % in the visible region. The FESEM observation indicated that the TiO2 surface morphology is highly sensitive to the increasing of dopant concentration. The FTIR spectroscopic results confirmed the presence of functional chemical bonding in the deposited films, as evidenced by the reflectance spectra. The ethanol sensing properties of 3 % Sm doped TiO2 films found to exhibit rapid response time at 32 s and a recovery at 20 s for 200 ppm at room temperature for 200 ppm concentration. Moreover, 3 % Sm doped TiO2 thin film electrical resistance, which was measured at 0.6 × 106 O, decreased significantly compared to other materials, indicating enhanced gas sensing properties.

Ag Incorporated MoO3 Thin Films and Fabrication of Ag/MoO3/p-Si Structured Photodiode

MoO3 have been widely investigated for their applications ranging from electronics to energy storage. Orthorhombic structured MoO3 thin films were prepared on a glass substrate. The Ag doped materials to add the MoO3 in different concentrations (1%, 3%, 5%) at Wt% with MoO3 precursor and synthesis was done using the spray pyrolysis method. X-ray diffraction revealed the incorporation of Ag in the MoO3 orthorhombic structure. FE-SEM images showed more dispersive and rod shapes than Agi-doped MoO3 and pure MoO3 respectively. The jet nebulizer spray pyrolysis technique for fabrication of n-Ag: MoO3/p-Si photodiodes makes it suitable for good response photo-detecting applications.

Preparation and characterization of innovative VSbO4 thin films via nebulized spray pyrolysis technique

Preparation and characterization of innovative VSbO4 thin films via nebulized spray pyrolysis technique

Improved photo sensing behavior of the terbium doped In2S3 thin films synthesized by spray pyrolysis technique

In the present work, undoped In2S3 and varying concentrations of Tb (1, 2, 3, 4 & 5 wt%) doped In2S3 thin films were synthesized using the economical and nebulizer spray pyrolysis technique for studying their photosensing characteristics at room temperature. X-ray diffractometer (XRD) studies showed the diffraction pattern of the thin films exhibits a cubic- β phase of In2S3 and the highest crystallite size of 61 nm was observed for the In2S3: Tb (2wt%) thin film. The morphological & elemental analysis showed that all the synthesized thin films exhibit homogeneous non-uniform crystal morphology with the existence of S, In, Tb compounds with their distinct composition. From Ultraviolet-Visible(UV–vis) studies, all the prepared thin films exhibit maximum absorption in the UV region with a minimum bandgap of 2.85 eV for the In2S3:Tb (2wt%) thin film. Also, the Photoluminescence (PL) spectra showed that the In2S3:Tb (2wt%) thin film possesses two large intense emission peaks around ∼470 nm (Yellow) and 530 nm (green). Finally, the photo sensing studies showed that the fabricated In2S3:Tb (2wt%) thin film photodetector showed better photocurrent, Responsivity (R), Detectivity (D*), External Quantum Efficiency (EQE), Response/Recovery time values of ∼12.5 μA, 0.296 AW−1, 7.75 × 1010 Jones, 60%, 2.9/3.6 s, respectively indicating the device better suitable for commercial photodetector application.

Improvement in ammonia gas sensing properties of La doped MoO3 thin films fabricated by nebulizer spray pyrolysis method

In the present work, different doping concentration (0, 1, 2, 3, 4 and 5 wt%) of Lanthanum (La) doped Molybdenum trioxide (MoO3) thin films were prepared using low cost Nebulizer spray pyrolysis (NSP)technique. The crystalline, morphology, optical and gas sensing properties of thin films were investigated. The presence of monoclinic MoO3 structure was confirmed through the XRD investigation for all the samples with highest crystallite of 61 nm was observed for 2 wt% La doped MoO3 thin film. The surface morphology of the produced thin films exhibits a reticulate nanofibrous mesh shape with increased particle size and porosity on addition of 2% La dopants in MoO3.The UV–Vis results showed the band gap values for the prepared thin films in the range 3.12–3.26 eV and the minimum bandgap was observed for the 2 wt% of La doped MoO3 thin film. Also the PL results confirmed the presence of more oxygen vacancies for the 2 wt% of La doped MoO3 thin film. The NH3 gas sensing study was conducted for the prepared films at room temperature, the 2 wt% of La doped MoO3thin film exhibits a maximum sensor response of 900, faster response times (28 s and 2.9s) compared to other fabricated devices. The results suggest that the 2% La doping in MoO3 could be an optimum doping concentration for the preparation of commercial NH3 gas sensors.

Enhanced sensing properties of Zn-doped MoO3 thin films developed using a nebulizer spray technique

Zn-doped Molybdenum trioxide (MoO3:Zn) thin films were coated on glass substrates using a nebulizer spray pyrolysis technique to apply ammonia (NH3) gas sensing. According to the structure examination, the crystallite size of the as-fabricated thin films is 64–77 nm. Field Emission Scanning Electron Microscopy (FESEM) images of the films confirm the formation of nanograins with islets-like shapes. In addition, Ultraviolet–Visible (UV–Vis) and photoluminescence (PL) studies were used to examine the samples optical bandgap and structural defects. Further, the MoO3: Zn sample's gas-sensing properties for ammonia detection were assessed at ambient temperature. The observed gas response of the MoO3:Zn3% sample was 20,900, and faster response and recovery times of 66s/9s. Furthermore, we observed that the MoO3:Zn3% sensor had exceptional ammonia selectivity.

Unraveling the role of solvent type in the physical and chemiresistive gas sensing properties of nebulizer-sprayed CuO films

Copper oxide thin films were grown via a nebulizer spray pyrolysis technique using five different solvents. The XRD patterns revealed that the CuO films prepared with alcoholic solvents are more crystalline andRaman analysis confirmed the crystalline quality of the films. The sample was prepared with an ethanolic solvent, producing a hierarchical, fiber-like morphology. EDAX spectra confirmed the presence of copper and oxygen in CuO films. XPS analysis showed a significant reduction of oxygen species in ethanol compared to water as a solvent. The film deposited with an ethanolic solution showed the lowest bandgap of 1.7 eV. PL spectra showed strong emission at 628 nm. Lifetime studies suggest that the enhancement in the decay lifetime of CuO films can be advantageous for optoelectronic applications. CuO thin films deposited with alcoholic solvents exhibited lower resistance values. VOC detection was employed by the CuO-based gas sensors. i.e., acetone, ethanol, and toluene.

Fabrication of crack-free PbS thin films by Jet nebulizer spray pyrolysis technique for enhancing optoelectronic applications: An effect of Ce3+ doping concentrations

The current study describes the fabrication of 0, 1, 3, and 5% Ce- doped PbS thin films by Jet nebulizer spray pyrolysis technique (JNSP) for photo-sensing application. XRD spectra revealed the cubic structure of Ce-doped PbS thin films. The crystallite size of PbS decreased with increasing the Ce doping concentration, suggesting the inclusion of the Ce atom into the PbS crystal lattice. FESEM results revealed that the samples had triangle-shaped nanostructured PbS thin films and that Ce doping could change the morphology into an aggregated pattern. The XPS spectra confirmed the presence of Pb, S, and Ce. The optical absorbance of PbS thin films significantly improved with Ce doping. The red shift in the absorption spectrum indicated a decrement in the bandgap value of PbS after adding Ce. Finally, the photo-sensing experiments show that 5% Ce-doped PbS thin films had the highest Ps (2895.21%), R (208.33 mA/W), and D*(3.379 × 1010 Jones) than all other fabricated devices, suggesting that the Ce-doped PbS thin films may be promising photodiode for commercial optoelectronic devices application.

High photocurrent performance of nebulizer sprayed Bi2S3 thin films by a novel Cu-La doping strategy

Nowadays, chalcogenide-based thin layers are proving a promising light-absorbing material with low cost and are technologically suitable for light to current conversion applications. In this study, for the first time, pristine Bi2S3, Bi2S3:Cu2%, Bi2S3:La2%, and Bi2S3:Cu2%:La2% thin films were prepared by nebulizer spray pyrolysis technique on a glass substrate at 300 °C. The obtained XRD pattern confirms the orthorhombic structure of Bi2S3 and possesses a maximum crystallite size of 38 nm for Bi2S3:Cu: La co-doped sample. Images taken with a FESEM analysis showed the unformed distribution of round shaped grains without any cracks and co-doping leads to the development of slight cluster formation. The optical absorbance spectra of the thin films were observed from the wavelength of 350 nm to 1000 nm, and the co doping process highly strengthen the optical absorbance, which is prerequisite for an efficient photodetector. A lower band gap value of 1.7 eV is achieved for Bi2S3: Cu: La thin film. From PL studies, defect emission bands around ∼325 and 525 nm related to band edge emission and sulfur vacancies are obtained. Further, UV photosensing properties of each sample were evaluated. Commendable performance with maximum responsivity (1.24 × 10−1 AW−1), detectivity (1.13 × 1010 Jones), and EQE (40%) were achieved for Bi2S3:Cu:La-sample. The enhanced figures-of-merit are attributed large crystalline size, good crystallinity, lower bandgap and crack free surface. The photo sensing results may widen the field of photosensing application.

Impact of Nd doping in Bi2S3 thin films coated by nebulizer spray pyrolysis technique for photodetector applications

In this study, cost effective & scalable nebulizer spray pyrolysis approach was used to produce varying concentrations of Bi2S3:Nd (0, 1, 3, 5 wt%) thin films on glass substrates and the effect of Nd dopants on the crystalline, morphological, optical and photo sensing properties of the Bi2S3 thin films were studied. From the XRD results, the diffraction pattern of the prepared Bi2S3:Nd thin films exhibits an orthorhombic structure for all concentrations of Nd dopants with a predominant peak along (130) plane. Upon increasing the concentration of Nd dopants up to 3 wt% the predominant peak intensity increases with an increase in crystallite size of 25 nm and decreases with a further increase in the incorporation of Nd dopant. The surface morphological studies showed uniform nanocrystalline morphology for all the Bi2S3 thin films. The UV–Vis absorption studies revealed higher absorption of the prepared thin films over UV region and narrowing of the energy gap from 2.18 to1.63 eV with the incorporation of Nd dopant from 0 to 3%, repectievely. The photo sensing properties of the fabricated devices showed higher responsivity (R), detectivity (D*), EQE, and rapid rise/fall time of 1.36 × 10−1 A/W, 3.05 × 1010 Jones, 43%, and 0.1/0.2 s for Bi2S3:Nd 3 wt% thin film photodetector confirming the suitability of the device for commercial photodetector applications.

Photo sensing properties of yttrium doped In2S3 thin film fabricated by low prize nebulizer spray pyrolysis technique

In the present study, a novel higher quality In2S3: Y (0, 1, 2, 3, 4, and 5 wt%) thin films were prepared using the nebulizer-aided spray pyrolysis process for photo sensor applications. The association between the concentration of precursor doping and several distinguishing characteristics in the 0–5% range was examined. The produced films were characterized for microstructure, morphology, composition, and optical and fabricated device's photodetection characteristics. X-ray diffraction pattern confirms the cubic phase of In2S3 with a preferential orientation along (400). FESEM (field emission scanning electron microscope) revealed the formation of nanograins with dot-like particles. Additionally, adding 2% Y in2S3 film increases the UV absorption and lowers the energy gap from 2.74 to 2.69 eV. Three emission peaks at 330, 345, and 525 nm were visible in the Photoluminescence spectra, confirming the existence of more defects with 2%Y dopant. The fabricated samples demonstrated remarkable U.V. photoresponse and photoelectric characteristics at 5 V bias voltage. The highest response (4.49 10−1 A/W), detectivity (3.23 1011 Jones), external quantum efficiency (105%), and rapid photoswitching speed were observed for 2% Y doped In2S3film. We further verified that the UV photo-sensing properties were considerably altered by the concentration of the Yttrium dopant used.

Noticeable effect of coating temperature on Co3O4 thin films developed through low-cost nebulizer spray pyrolysis for photo-sensing applications

Cobalt oxide thin films are synthesized at various temperatures from 275 to 375 °C using a nebulizer spray pyrolysis technique. Different characterization approaches are used to investigate the effects of coating temperature on the characteristics of coated thin films. The deposited films have a cubic structure with a preferred orientation along the (111) direction. Field Emission Scanning Electron Microscope (FESEM) reveals the grain size of the samples as the coating temperature rises. The energy dispersive x-ray analysis (EDS) spectra confirm that the growing film is primarily made up of Co and O. The optical absorption spectra show an increase in absorption with increasing coating temperature. The band-gap energy values are lowered by 2.12, 2.10, 2.09, 2.01, and 2.05 eV with respect to the coating temperatures of 275, 300, 325, 350, and 375 °C, respectively. The observed photoluminescence(PL) spectra exhibit the band edge and defect-based emissions for all the films. Studies of current (vs) voltage revealed ohmic nature up to 350 °C coating temperature. At coating temperature 375 °C hysteretic behavior of film is observed because of the increasing number of vacancies and defective sites, which act as trap of charge carriers. The photo-detection capabilities of these coated Co3O4 thin films were investigated using optoelectronic characteristics. The optical and electrical properties have also been controlled by the fusing temperature. The Co3O4 (350 °C) produce high photocurrent (8.84 × 10−7A), external quantum efficiency (11.6%), detectivity (3.5 × 109 Jones), responsivity (4.99 × 10−2 AW−1) and has the shortest rise/decay time among the constructed photo-detectors. These findings show the tuning of the properties of Co3O4 by optimizing the coating temperature for the fabrication of effective photo-detectors.

Enhancement of optoelectronic properties of PbS thin films grown by Jet nebulizer spray pyrolysis technique for photodetector applications: an impact of substrate temperature

Enhancement of optoelectronic properties of PbS thin films grown by Jet nebulizer spray pyrolysis technique for photodetector applications: an impact of substrate temperature