Ketan P. Gattu

Bio-green synthesis of Ni-doped tin oxide nanoparticles and its influence on gas sensing properties

Considering the potential applications of transition metal doped nanostructured materials and the advantages of novel, cost-effective and environmentally friendly biosynthesis methods, Ni-doped SnO2 nanomaterials have been synthesized using remnant water (ideally kitchen waste) collected from soaked Bengal gram bean (Cicer arietinum L.) extract. The structural and optical properties of the Ni-doped SnO2 nanostructures were studied using various techniques such as UV/visible spectroscopy, FT-IR spectroscopy, X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The SEM and TEM images and the XRD results of the biosynthesized Ni–SnO2 nanoparticles reveal a uniform size distribution with an average size of 6 nm and confirmed the formation of a rutile structure with the space group (P42/mnm) and the nanocrystalline nature of the products with a spherical morphology. Subsequently, Ni-doped biosynthesized SnO2 nanoparticles were coated onto a glass substrate using the doctor blade method to form thin films. The NO2 sensing properties of the materials have been studied in comparison with other gases. The reported gas sensing results are promising, which suggest that the Ni-dopant is a promising noble metal additive to fabricate low cost SnO2 based sensors.

Room Temperature Ammonia Gas Sensing Properties of Biosynthesized tin Oxide Nanoparticle Thin Films

The authors are thankful to UGC-DAE Consortium for Scientific Research, Indore (Project Ref. No.: CSR-I/CRS-48/48) and UGC, New Delhi (F. No. 41-370/2012 (SR)) for the financial support. We are also thankful to the Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad for providing the laboratory facility.

Annealing effect on Cu2S thin films prepared by chemical bath deposition

In present work Cu2S thin film fabricated on glass substrate by simple, cost effective chemical bath deposition method subsequently it annealed at 150°c.These films were studied for their structural, optical and electrical properties using X-ray diffraction, UV-vis spectrophotometer and I-V system. The results show successful synthesis of Cu2S thin films and improvement in crystalline nature of the thin film which resulted in reduced bad gap and resistance of the film. Thus these thinfilms prove to be a promising candidate for solar cell application.

Economic approach for fabricating nontoxic Cu2ZnSnS4 (CZTS) thin films for solar cell applications

In the present work, Cu2ZnSnS4 (CZTS) thin films have been fabricated onto the glass substrate by simple and economic chemical bath deposition technique, using optimized temperature of 50°C and deposition time of 60 min, which is significantly lower than earlier reports. The CZTS thin films were characterized for morphological, compositional, optical and electrical properties using scanning electron microscopy, energy dispersive X-ray analysis, UV-vis spectrophotometer and I-V system for photosensitivity.

One step synthesis of kestarite Cu2ZnSnS4 thin film by simple and economic chemical bath deposition method

Nanostructured Cu2ZnSnS4 (CZTS) Kesterite thin film has been synthesized by inexpensive chemical bath deposition method in one step on glass substrate. Structural, optical and electrical properties of as grown Kesterite CZTS thin film have been investigated. The Kesterite structure of the CZTS thin film has been confirmed by XRD. Whereas polycrystalline nature of the film has been confirmed from the concentric ring pattern obtained from TEM–SAED. Kesterite CZTS film shows higher absorption in visible region with band gap Eg =1.68 eV. The obtained band gap is in the range of optimum value of solar spectrum for solar radiation, results in higher absorption of light. I-V measurement in dark and under illumination of light (200 W/cm2) reveals high photocurrent in dark as well as in light. The calculated photosensitivity and photoresponsivity were 52 % and 16.9 µA/W respectively.

Temperature dependent fabrication of cost-effective and nontoxic Cu2ZnSnS4 (CZTS) thin films for solar cell

In the present work, Cu2ZnSnS4 (CZTS) thin films have been fabricated onto the glass substrate by simple and economic chemical bath deposition technique1, and the effect of deposition temperature is reported. The deposition temperatures used were 50°C and 60°C for a deposition time of 60 min, which are significantly lower than earlier reports. These CZTS thin films were characterized for optical, electrical, morphological and elemental properties using, UV-Vis spectrophotometer, I-V system for photosensitivity, two probe resistivity system for resistivity, scanning electron microscopy, energy dispersive spectroscopy and Raman spectroscopy.

Hydrothermal synthesis of MnO2 thin film for supercapacitor application

MnO2 thin films were directly grown on stainless steel mesh via a facile hydrothermal method. The structural properties revealed the formation of delta MnO2. The capacitive performance of the as-obtained MnO2 electrode was evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The synthesized electrode showed a high specific capacitance of 321 F g−1 at 5 A g−1. The excellent electrochemical performance identifies the MnO2 as a promising electrode material for next-generation energy storage devices.MnO2 thin films were directly grown on stainless steel mesh via a facile hydrothermal method. The structural properties revealed the formation of delta MnO2. The capacitive performance of the as-obtained MnO2 electrode was evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The synthesized electrode showed a high specific capacitance of 321 F g−1 at 5 A g−1. The excellent electrochemical performance identifies the MnO2 as a promising electrode material for next-generation energy storage devices.

Growth of nanocrystalline Zn0.75Mg0.25S thin film by solution growth technique and their characterization as a window layer for solar cell

ABSTRACT Zn0.75Mg0.25S thin film was grown by solution growth technique. The as-grown thin film was examined to study its structural and optoelectronic properties. The formation of pure ZnMgS/O phase with wurtzite structure was confirmed by XRD. Optical bandgap (∼3.69 eV) was estimated through Taucs plot obtained from UV-Vis spectroscopic data analysis. The existence of ZnMgS/O phonons was confirmed from the peaks obtained in Raman spectra. The PL spectrum shows band edge near UV emission. Decrease in resistance after light illumination was observed in I-V characteristics results in 98% photosensitivity.

Effect of quantum confinement on photosensitivity in ZnS thin film grown by facile chemical bath deposition

ABSTRACT Nanostructured ZnS thin film has been successfully synthesized by CBD method. Face-centered cubic structure with average crystallite size of 3.4 nm suggests the formation of quantum dots, confirmed by XRD. The ZnS thin film represents higher absorption in UV region with an energy band gap of 3.77 eV, slightly shifted at higher scale due to quantum size effect. The I-V curve in dark and under light illumination (200 watts) shows a decrease in resistivity from 1.16 MΩ-cm to 0.77 MΩ-cm resulted in 34% photosensitivity. The calculated photosensor efficiency and photoresponsivity were 1.51% and 11.8 nA/W2 respectively.

A high visible light ZnMgS nanorod thin film photosensor by solution growth technique

ZnMgS thin film was grown by cost effective, simple one step solution growth technique on silica glass substrate. A thin film was characterized for structural, morphological and an I-V characteristic. The X-ray diffraction pattern (XRD) pattern shows that, ZnMgS thin films have mixed phase of hexagonal and zinc blende crystal geometry. Scanning electron microscopy (FE-SEM) clearly show bunches of nanorods on entire surface of film. The I-V measurement under dark and illumination of 100 mW/cm2 shows 90.44% photosensitivity.ZnMgS thin film was grown by cost effective, simple one step solution growth technique on silica glass substrate. A thin film was characterized for structural, morphological and an I-V characteristic. The X-ray diffraction pattern (XRD) pattern shows that, ZnMgS thin films have mixed phase of hexagonal and zinc blende crystal geometry. Scanning electron microscopy (FE-SEM) clearly show bunches of nanorods on entire surface of film. The I-V measurement under dark and illumination of 100 mW/cm2 shows 90.44% photosensitivity.