Surface reconstructions for InAs„001... studied with density-functional theory and STM
نویسندگان
چکیده
The stability of different surface reconstructions on InAs~001! is investigated theoretically and experimentally. Density-functional theory calculations predict four different surface reconstructions to be stable at different chemical potentials. The two dominant reconstructions are the b2 ~234! for high As, and the a2 ~234! for low As overpressure. This trend is confirmed by scanning tunneling microscopy of carefully annealed InAs~001! surfaces. A similar behavior is predicted for GaAs~001!.
منابع مشابه
Atomic scale structure of InAs(001)-(2 4) steady-state surfaces determined by scanning tunneling microscopy and density functional theory
The structure of InAs(0 0 1)-ð2 4Þ surfaces equilibrated under typical MBE conditions is studied by scanning tunneling microscopy (STM). Depending on the magnitude of the As flux, typical surfaces are found to contain a mixture of a2ð2 4Þ and b2ð2 4Þ reconstructions. The relative populations of the a2 and b2 reconstructions are found to depend on substrate temperature and the magnitude of the A...
متن کاملIn situ threshold photoemission yields correlated to surface reconstructions of InAs „001..
Threshold photoemission yields for As and In terminated reconstructions of InAs ~001! are measured in situ and the variation of the photoyield is correlated with the surface stoichiometry. A significant excess in the measured photoelectron yield is found for the In terminated surfaces. These results are compared to a semiempirical model based on density-functional theory calculations of the sur...
متن کاملStrain-induced change of surface reconstructions for InAs„001..
The effect of strain on the stability of different surface reconstructions on InAs~001! is investigated with density-functional theory calculations. The effects of isotropic as well as anisotropic tensile and compressive strain is investigated, and the results are presented in corresponding equilibrium phase diagrams. I find that the range of stability for any of the relevant reconstructions ca...
متن کاملStatistical Analysis of Surface Reconstruction Domains on InAs Wetting Layer Preceding Quantum Dot Formation
Surface of an InAs wetting layer on GaAs(001) preceding InAs quantum dot (QD) formation was observed at 300°C with in situ scanning tunneling microscopy (STM). Domains of (1 × 3)/(2 × 3) and (2 × 4) surface reconstructions were located in the STM image. The density of each surface reconstruction domain was comparable to that of subsequently nucleated QD precursors. The distribution of the domai...
متن کاملThe NECIS Focus in Nanotechnology Editors
The atomic surface structure of compound semiconductors plays a large role in the growth of semiconductor films and the final microstructure of the film. During growth of InxGa1−xAs films, a mixed-termination surface consisting of a (4x3) reconstruction with common binary InAs or GaAs reconstructions, such as the α2(2x4), has been observed. We have used Density Functional Theory (DFT) to determ...
متن کامل