A Computational Study on the Variation of Bandgap Due to Native Defects in Non-Stoichiometric NiO and Pd, Pt Doping in Stoichiometric NiO

This paper presents a computational study of non-stoichiometric nickel oxide in a 64-cell NiO system to model and validate localized heating effects due to nanosecond laser irradiation. Variation in the Bandgap of NiO is studied as a function of varying concentrations of native defects, ranging from...

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Bibliographic Details
Main Authors: Srikanth Itapu, Vamsi Borra, Faramarz Mossayebi
Format: Article
Language:English
Published: MDPI AG 2018-12-01
Series:Condensed Matter
Subjects:
Online Access:https://www.mdpi.com/2410-3896/3/4/46
Description
Summary:This paper presents a computational study of non-stoichiometric nickel oxide in a 64-cell NiO system to model and validate localized heating effects due to nanosecond laser irradiation. Variation in the Bandgap of NiO is studied as a function of varying concentrations of native defects, ranging from 0 to 25%. It is observed that there is a slight increase in the bandgap from 3.80 eV for stoichiometric NiO to 3.86 eV for Ni-rich NiO and to 3.95 eV for O-rich NiO. It is hence deduced that the experimental laser irradiation leads to simultaneous reduction of Ni<sup>2+</sup> ions and the oxidation of NiO as the number of laser pulses increase. As well, a detailed study on the effects of doping nickel family elements, i.e., palladium (Pd) and platinum (Pt), in stoichiometric NiO is presented. A bandgap decrease from 3.8 eV for pure NiO to 2.5 eV for Pd-doping and 2.0 eV for Pt-doping for varying doping concentrations ranging from 0&#8315;25% Pd, Pt, respectively, is observed.
ISSN:2410-3896