Surface structure of bismuth terminated GaAs surfaces grown with molecular beam epitaxy

► Deposited 2.4 ML (or 6 ML with As4) of Bi onto GaAs(001) β2(2 × 4) surface. ► Reflective high-energy electron diffraction shows (1 × 3) and (4 × 3) patterns. ► Scanning tunneling microscopy (STM) reveals β(4 × 3) reconstruction. ► High number of up-down step edge pairs in STM suggest origin of Bi smoothing effect. ► Synchrotron photoemission spectra indicate α(4 × 3) and γ(4 × 3) reconstructions.