Search

The slow evaporation technique was adopted for the growth of L-tyrosine doped Thiourea (Bis) Cadmium Acetate (CTA) single crystal. The doped crystals were characterized by powder X-ray diffraction, FT-IR analysis, SHG Studies, UV-vis and Vickers microhardness studies. The UV-visible absorption spectrum is found to have improved optical parameters than pure CTA. The optical study revealed that the doped CTA crystal has high transmission with low cut off wavelength of 290 nm. The optical band gap was found to be 4.14 eV. The Second harmonic generation efficiency measured using Nd-YAG laser is 3.64 times higher than pure CTA. [ABSTRACT FROM AUTHOR]

In the present report, influence of annealing temperature variations on the optical, morphological, and structural properties of chemically deposited nanocrystalline zinc-selenide thin films is studied employing an X-ray diffractometer, scanning electron microscope, and UV spectroscope. As-synthesized and annealed films exhibit nanocrystalline nature with cubic structure. The result shows that ZnSe thin films contain spherical particles that are composed of nanocrystals ranging from 3 to 7 nm crystallite size. The SEM studies reveal that the inter-crystalline spaces have been found to be reduced with an increase in grain size as annealing temperature increases. The EDS data reveal that the obtained thin films are rich in selenium. However, thermal annealing assisted to reduce the non-stoichiometric nature of the films by reducing selenium content that was found to be reduced with a rise in annealing temperature. The reduction in strains and dislocation density was observed after the annealing process. The band-gap energy was found to be raised from 2.56 to 2.76 eV with a rise in annealing temperature. The transmittance of more than 80% was recorded by as-synthesized and annealed films as well. [ABSTRACT FROM AUTHOR]

Cu2ZnSnS4 is suitable for high-performance thin-film solar cell because of its high absorbance coefficient, presence of non-toxic elements, excellent optoelectronic properties, and a near-perfect direct band gap. The effect of thermal annealing time (1–4 h) on the optical, morphological, and structural properties of Cu2ZnSnS4 coated through a simple solution processable method has been studied in the present work. All the CZTS films are crystalline in nature with kesterite structure as shown by X-ray diffraction studies. Crystallite size, strain, and dislocation density were calculated. However, no notable changes in these parameters were obtained by varying the annealing time in the above range. Field emission scanning electron microscopy images show good quality compact films with particle size in the order of 10–15 nm. Absorption spectroscopy results show an optical band gap of 1.46 eV. Raman spectroscopy was used to check binary or ternary phases present. It shows that the impurity phase decreases and the pure Cu2ZnSnS4 phase was obtained by increasing the annealing time to 3 and 4 h. [ABSTRACT FROM AUTHOR]