Observation Of A (3~(1/2) × 3~(1/2))r30° Reconstruction On O-polar Zno Surfaces

摘要

Low energy electron diffraction shows a (3~(1/2) × 3~(1/2))R30° reconstruction on O-polar ZnO surfaces after a tube furnace annealing process commonly used to create atomic-height steps. This reconstruction is also produced in situ under conditions having an extremely low hydrogen background. X-ray photoelectron spectroscopy suggests H stabilizes the (1 × 1) termination that has been extensively reported. The (3~(1/2) × 3~(1/2))R30° reconstruction is stable against H_2, N_2, and air, although its formation is suppressed when preparation occurs under a H_2 background. Therefore, caution must be taken when using annealed O-polar ZnO substrates, as reconstruction will affect the nature of the surface and, thus, the growth interface.