Band gap engineering of cadmium selenide nanocrystals using 120 MeV Ag7+ swift heavy ions, alongside theoretical evidence through PBE plus U analysis

摘要

The interaction of 120 MeV Ag7+ swift ions with the chemically prepared cadmium selenide nanocrystals have been studied in this work through XRD data analysis. Atomic force microscopic study provides the information that with SHI irradiation, average grain size increases and surface modification takes place. Thermal spike model gives an idea about the changes in the lattice structure due to SHI irradiation, which induces lattice geometry reorientation. Such changes in lattice geometry result in modification of band structure as well as density of states of the bands and therefore modification in the band gap of the prepared sample takes place. Theoretical study of the band gap tuning has been performed using first principles based on Quantum espresso Code through PBE + U analysis, which supports the results as obtained from experimental diffuse reflectance spectra and Photoluminescence spectral study. Hence, both the experimental and theoretical study confirm the band gap engineering of CdSe nanocrystals through SHI irradiation. (C) 2020 Elsevier B.V. All rights reserved.