An ab initio study of potassium chemisorption on the GaAs(110) surface

Abstract

Different possible adsarption sites of potassium atoms on a gallium arsenide (110) surface have been investigated using ab initio self-consistent unreSuicted HarireeFock tot& energy cluster calculations with Hay-Wadt effective core potentials. The effects of electron correlarion have been included by invoking the concepts of my-body perturbation theory and are found to be highly significant. We find that the K atom adsorption at a site modelled with a KGa5As4H12 cluster is most favoured energetically, followed by K adsorption^ at the site modelled with the KGalAssH12 clusta. For molecular potassium. a parallel approach positron modelled by a KzGaihH12 cluster is most favoured energefidy followed by a vertical approach position modelled by a K2GalAs~H14 cluster. The effects of charge transfer from K and Kz to the GaAs surface as well as the possibilities of metallization are also analysed and discussed.

A cluster study of aluminum adsorption on Ga-rich GaAs(100)(2 × 1) and β (4 × 2) surfaces

“…The values for the exponents for gallium and arsenic were found to be d Ga = 0.170 and d As = 0.280 respectively. This procedure has been previously used in out studies of alkali adsorptions on the GaAs (110) surface [22][23][24][25][26]. The value of the exponent for aluminum is found to be d Al = 0.218 ( Figure 1 In this work we considered clusters representing two different reconstructed surfaces, namely the (2 × 1) and β (4 × 2) surfaces [1,2].…”

Adsorption and dissociation of H2O on the Ga-rich GaAs(001)-(4×2) surface: DFT and DFT-D computations with a Ga7As8H11 cluster model

“…Cluster model plays a significant role in studying the adsorption problems involving the GaAs surface [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Cluster model is able to present the essential adsorption character with relatively low computational cost.…”

“…Cluster model is able to present the essential adsorption character with relatively low computational cost. Different sized clusters have been constructed to model the GaAs surface [15][16][17][18][19][20][21]. The adsorption sites and energies of atomic species on the GaAs surface were investigated with the cluster models [15][16][17][18][19][20][21][22].…”

“…Different sized clusters have been constructed to model the GaAs surface [15][16][17][18][19][20][21]. The adsorption sites and energies of atomic species on the GaAs surface were investigated with the cluster models [15][16][17][18][19][20][21][22]. The adsorption and dissociation mechanisms of molecules on the GaAs surface were also studied with the cluster models [23][24][25][26][27][28][29][30][31][32].…”