94 Computational and Experimental Research in Materials and Renewable Energy (CERiMRE) Volume 4, Issue 2, page 94-101 eISSN : 2747-173X Submitted : August 20, 2021 Accepted : October 25, 2021 Online : November 24, 2021 DOI : 10.19184/cerimre.v4i2.28375 Study of Electronic Properties of GaAs Semiconductor Using Density Functional Theory Fikri Abdi Putra 1,a , Endhah Purwandari 1 and Bintoro S. Nugroho 2 1 Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Jember, Jalan Kalimantan No. 37, Jember 68121, Indonesia 2 Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Tanjungpura, Jl. Prof. Dr. H. Hadari Nawawi, Pontianak, Indonesia a fikriabdi21@gmail.com Abstract. The properties of GaAs material in zinc blende type was calculated using Hiroshima Linear Plane Wave program based on the Density Functional Theory. This calculation aims to determine electronic properties of GaAs material are based on Density of States and energy band structure. This simulation’s results are DOS shows that hybridization of s orbital of Ga with s orbital of As provides covalent properties. The simulation of energy band structure from GaAs material indicates that semiconductor properties of GaAs is direct band gap. The energy band gap results obtained for GaAs is 0.80 eV. The computational result of the energy band gap calculation form HiLAPW has better accuracy and prediction with good agreement within reasonable acceptable errors when compared to some other DFT programs and the results of the experimental obtained. Keywords: DFT, HiLAPW, GaAs, Electronic Properties, Density of States, Energy Band Structure, Energy Bandgap Introduction The study of materials applied as electronic materials, magnetic materials, spintronic materials, optical materials, etc. has a very important role in the development of science and technology. A widely studied material in this regard is Gallium Arsenide (GaAs). Analysis of its characteristics is used for the development of electronics and instrumentation technology. The performance of GaAs materials selected to be applied as optical materials for lasers [1], detectors and photovoltaics [2], also as substrate materials [3,4], are influenced by their electronic properties. The electronic properties could be analyzed from the characteristics of the density of state (DOS) and energy band diagram, as well as the band gap of the material. The calculation of density of state (DOS) and energy band of GaAs have been reported by Rany and Kumar [5] using Density Functional Theory implemented by SIESTA code, in local density approximation with exchange correlation parameterized by Perdew and Zunger. The GaAs energy band gap, which was simulated using the zincblende structure, was 0.4 eV. Experimentally, the measurement of the energy gap was carried out by Kusch et al using Raman Resonance Spectroscopy. At room temperature and 0 K, the energy gaps of GaAs with a zincblende crystal structure were obtained at 1.425 eV and 1.519 eV, respectively [6]. In this paper, we perform the calculation of band gap of GaAs zincblende type based on the band structure using DFT method through HiLAPW program package. It is designed to perform band- structure calculations based on the density functional theory (DFT), with some features including scalar-relativistic spin-polarized calculations within the local (spin) density