Browsing by Author "Amare, Andinet"

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    Electronic Structure of 2d-Gallium Arsenide as Studied Using First Principles Density Functional Theory (DFT)
    (Addis Ababa University, 2020-08-23) Amare, Andinet; Amente, Chernet (PhD)
    In this thesis we have calculated electronic structure of 2D-GaAs within the first principles using Quantum ESPRESSO pacakage. We optimized lattice constant and identified the nature and values of band gap of Zinc Blende structure gallium aresnide (GaAs). Norm-conserving pseudopotential is used for the self-consistent calculation, and the Generalized Gradient Approximation (GGA) for the exchange correlation. An optimum lattice constant of 7.4Å, 6.1Å, and 5.7Å, respectively, is obtained for 1D, 2D, and 3D, and in close agreement with the experimental value 5.65Å. 2-D GaAs is known to have a gap of 1.8 eV which is in close agreement with previous observations [45], but has 25.9 % error to the experimental value 1.43 eV [42]. This work clearly explains that lattice constant increases with decrease in crystal size. Moreover, we could identify the charge transfer between the Ga and As atoms. Generally we could make calculations and compare with its 1-D and 3-D structures results.