Influences of homogenous and heterogenous dopants on structural, electric, and thermodynamic properties of the gallium arsenide (GaAs) nanodot: A DFT study

Abstract

In recent times, low-dimensional semiconducting materials have drawn the attention of researchers due to their wide range of applicability in technological sectors. Among different semiconducting materials, gallium arsenide (GaAs) is the second most prominent materials for developing devices due to its direct band gap and high electron mobility. In this work, the geometric, electronic, and thermodynamic properties of the GaAs nanodot after consecutive doping with homogenous transition metals (Ir–Ir) and heterogeneous transition metals (Ir–Ru & Ir–Pd) have been investigated. The investigation has been performed by employing density functional theory (DFT) with B3LYP hybrid functional using LanL2DZ basis set. The investigation reveals that the GaAs nanodot gains more stability (−98 eV ∼ −468 eV for doped clusters and −21 eV for the pristine cluster) and becomes efficient which is confirmed by studying binding energy and bond lengths in the heterogeneous doping process rather than the sequential homogenous doping process. Moreover, the infrared (IR) spectra analysis confirms that all structures might be found naturally in a stable and true energy minima, except Ga₂As₂Ir₂Ru_2, because of the presence of imaginary frequency. Also, the band gap (1.2 eV–2 eV for all doped structures) exhibits a suitable semiconducting nature of the doped structures. The thermodynamic properties show that both homogenous and heterogenous doping techniques cause thermodynamic stability to the GaAs nanodot as well as make them more feasible. Finally, considering all the physicochemical properties it has been concluded that for GaAs nanodot, the heterogenous atom doping process is more efficient than the homogenous atom doping when the dopant number is the same.