Cs ADSORPTION ON GaAS(001) As-RICH β2 (2×4) AND Ga-RICH (4×2) RECONSTRUCTION PHASES: A FIRST-PRINCIPLES RESEARCH.

Using plane-wave ultrasoft pseudopotential method based on first-principles density functional theory (DFT), the adsorption of Cs atom on As-rich GaAs(001) β 2 (2 × 4) reconstruction phase and Ga-rich GaAs(001)(4 × 2) reconstruction phase are investigated. The adsorption energy, work function, dipole moment, ionicity, band structure and density of state (DOS) of Cs adsorbed GaAs β 2 (2 × 4) and (4 × 2) models are calculated. The stability and electronic structure of Cs adsorbed GaAs β 2 (2 × 4) and (4 × 2) models are compared. Result shows that β 2 (2 × 4) phase is stable than the (4 × 2) phase and after that Cs adsorption β 2 (2 × 4) phase is more beneficial for photoemission. [ABSTRACT FROM AUTHOR]