Arsenic-rich GaAs(0 0 1) surface structure

This article discusses the past 40 years of research covering the equilibrium thermodynamic properties of the arsenic-rich GaAs(0 0 1) surface, which is the starting surface for producing the majority of optoelectronic devices worldwide. A coherent picture of the observed surface structures, theoretical calculations, and experimental results will be presented. The interplay in surface-free-energy-reduction between reconstruction transformation and roughening is now well understood for the GaAs(0 0 1) surface and will be discussed. The recent confirmations of the structural models for the (2×4) and c(4×4) reconstructions as well as the discovery of preroughening aid in this understanding.