Growth and structural characterizations of chromium mixed molybdenum diselenides (CrxMo1−xSe2 (x=0.25, 0.50, 0.75)) single crystals

• It is quite possible to grow CrxMo1−x Se2 single crystals using iodine as a transporting agent at high temperature.
• EDAX confirms the stoichiometry and XRD pattern shows the MoSe2 type hexagonal structure.
• Spot pattern from the TEM images verify that grown crystals exhibit single crystalline nature.
• Optical microtopography images clearly show that screw dislocations takes place on the surface of the grown crystals.
• Indirect bandgap values are changed with change in chromium content in the stoichiometry of compounds.

A systematic study on structural, morphological and optical properties of chromium mixed molybdenum diselenides, CrxMo1−xSe2 (x=0.25, 0.50, 0.75) single crystals grown by chemical vapour transport (CVT) technique is reported. The grown crystals were characterized with the help of energy dispersive analysis by X-ray (EDAX), which gives the confirmation about the stoichiometry. The structural characterization was accomplished by X-ray diffraction (XRD) studies. The crystals are found to possess hexagonal structure. The lattice parameters, unit cell volume, crystallite size, strain and dislocation density have been also evaluated for these new crystals. The estimation of growth and deformation fault probabilities is further calculated. The selected area electron diffraction (SAED) showed spot pattern, indicating the as grown CrxMo1−xSe2 (x=0.25, 0.50, 0.75) to be single crystals. The grown crystals were examined under optical zoom microscope for their surface topography. The optical response of these crystals has been obtained by UV–vis–NIR spectroscopy at room temperature. Results of optical spectra have been analyzed on the basis of three dimensional models. All the results obtained are discussed in detail.