Confirmation of the presence of edge dislocations in the prepared FCC ZnTe nanocrystals from the study of structural analysis through the MWH method with added Fourier analysis (W-A method) of diffraction peaks

Abstract

Nanocrystalline ZnTe with cubic mono-phase has been synthesized by a wet-chemical synthesis process for the study of the presence of dislocations through X-ray diffraction peak profile analysis. The average size of the ZnTe nanocrystals has been determined from the High-Resolution Transmission Electron Microscopic (HRTEM) analysis as 21.9 nm. In the XRD pattern, (111), (200), (220), (311), and (400) diffraction planes have been observed, which confirms the formation of cubic mono-phase of ZnTe. For the extraction of microstructural details, the Rietveld refinement has been performed using Fullprof software and from this refinement, the lattice constant has been obtained as 6.17 Å under the space group of f-43. Here, X-ray diffraction peak has been analyzed through the Williamson-Hall (W–H) analysis method and the Warren-Averbach (W-A) analysis method. Williamson-Hall approach is based on the full-width at half-maxima analysis, whereas the Warren-Averbach method is related to the analysis of the Fourier transform of the broadened X-ray diffraction peaks. For considering and analyzing the anisotropic broadening of the peak, modified Williamson-Hall and modified Warren-Averbach methods have been used for the calculation of size, strain, and dislocation density. The presence of prominent edge dislocation of about 71 % has been confirmed from the anisotropic peak broadening study. In addition, the HRTEM image directly verifies the presence of edge dislocations in both the lattice planes of (111) and (220).