Vikas Sawant; D.A. Lavate; A.S. Khomane
Abstract
Aim of this work is to study the synthesis of CdS thin films by eco-friendly rout and analyze the change in structural and optical properties of material due to use of biomolecules as a stabilizing agent. The CdS thin films were deposited in lemon extract and ammonia solution separately by maintaining ...
Read More
Aim of this work is to study the synthesis of CdS thin films by eco-friendly rout and analyze the change in structural and optical properties of material due to use of biomolecules as a stabilizing agent. The CdS thin films were deposited in lemon extract and ammonia solution separately by maintaining the same physical parameters and analyzed for tailoring of structural and optical properties. Green-CBD method minimizes the use of toxic precursors and volatilization of ammonia solution. X-Ray Diffraction study indicates formation of face centered cubic crystalline phase predominantly for CdS thin films materials with change in grain size. SEM analysis revealed the formation of CdS nanospheres in ammonia while CdS nanocubes in lemon extract. The direct allowed band gap energy was observed in the order of 2.45 eV and 2.25 eV which were interesting for optical studies. UV-Vis Absorption spectra and PL spectra of thin films indicates the CdS thin film material has absorption maxima in visible (400-800 nm) region. As synthesized CdS thin films were applied for photodegradation of Rhodamine-B dye solution under sunlight. The CdS thin film material deposited by Green-CBD rout shows high efficiency for degradation of Rhodamine-B solution as compared to films deposited by CBD method.
Nanomaterials & Nanotechnology
Praveena G; Mohammed E.M.; Viji C.; Shyam Kumar S.
Abstract
Nickel ferrite (NiFe₂O₄) nanoparticles were synthesized using the sol-gel auto combustion method, and the powdered samples were calcined at two temperatures, 100°C and 200°C. The structure of nickel ferrite nanoparticles was determined using X-ray diffraction (XRD) patterns. The nickel ferrite ...
Read More
Nickel ferrite (NiFe₂O₄) nanoparticles were synthesized using the sol-gel auto combustion method, and the powdered samples were calcined at two temperatures, 100°C and 200°C. The structure of nickel ferrite nanoparticles was determined using X-ray diffraction (XRD) patterns. The nickel ferrite nanoparticle size was calculated using the Debye-Scherrer formula and was found to be 15.53 nm and 17.14 nm for 100 °Cand 200 °C. Field Emission Scanning Electron Microscopic (FESEM) analysis reveals that the samples exhibit spherical morphology with crystalline in nature and also show some agglomeration. The phase formation of nickel ferrite nanoparticles was further confirmed from the energy dispersive x-ray (EDAX) spectra which shows strong peaks for the existence of all the elements in it. The work investigates the magnetic properties of the samples and both the samples exhibit ferromagnetic behavior. The optical band gap obtained for the samples is 2.5 and 2.6 eV for N1 and N2 samples. The antimicrobial activity especially the anti-algal effect of NiFe₂O₄ nanoparticles on freshwater microalgae Chlorella pyrenoidosa in a dose-dependent manner is also reported.
Shailaja Jeetendra; Naveen C. Shivappa; Raghu Patel; Mahesh H. Matt
Abstract
Sb2Te3 thin films of different thickness ranging from 100 to 500 nm were prepared on glass substrate by thermal evaporation method. The effects of thickness on structural, optical and electrical properties of thin films were studied. XRD revealed that grain size increases from 1.1 to 98.7 nm with increase ...
Read More
Sb2Te3 thin films of different thickness ranging from 100 to 500 nm were prepared on glass substrate by thermal evaporation method. The effects of thickness on structural, optical and electrical properties of thin films were studied. XRD revealed that grain size increases from 1.1 to 98.7 nm with increase in film thickness. The internal strain and dislocation density decreased with increase in film thickness. The optical band gap decreases from 1.3 to 0.9 eV with increase in film thickness. AFM images indicated crystalline nature of Sb2Te3. Surface roughness increased up to 400nm after which it decreased. The resistivity decreases with increase in thickness at room temperature ranging from 2.9×10 -3 to 1.35×10 -4 ohm.cm. The work function and barrier height decreases as the film thickness increases from 5.45 to 5.05eV and barrier height from 0.3 to -0.1eV. The results elucidate that Sb2Te3back contact of 400 nm thickness is ideal and efficient to be used in CdTe solar cell.
Geeta Rana; Umesh C. Johri
Abstract
Magnetite nanoparticles with particle size ~ 10 and 16 nm are synthesized by varying pH of the initial solution during chemical co-precipitation method. The X-ray diffraction patterns confirm the formation of spinel phase; however, the Raman spectra show an impure phase of antiferromagnetic Fe2O3 in ...
Read More
Magnetite nanoparticles with particle size ~ 10 and 16 nm are synthesized by varying pH of the initial solution during chemical co-precipitation method. The X-ray diffraction patterns confirm the formation of spinel phase; however, the Raman spectra show an impure phase of antiferromagnetic Fe2O3 in the sample of smaller nanoparticles (10 nm). The cation distribution of these nanoparticles is estimated using the lattice parameter. Lower saturation magnetization of these samples, as compared to bulk, has been attributed to larger surface area of these samples. Same aspect has also been investigated from the optical band gap variation of these nanoparticles. Almost one third value of magnetization of smaller nanoparticles compared to larger one is due to the presence of Fe2O3 phase. The motive of the present study is to correlate the properties of magnetite nanoparticles with the synthesis parameters like pH and hence to tune them according to particular applications.
)