GAN (0001)-(1X1) SURFACES - COMPOSITION AND ELECTRONIC-PROPERTIES

We use low energy electron diffraction, Auger electron spectroscopy, a nd ultraviolet and x-ray photoemission spectroscopy to study the surfa ce structure, stoichiometry, and electronic properties of n- and p-typ e GaN (0001) grown by metal-organic chemical vapor deposition. Ordered (1 x 1) surfaces with nearly stoichiometric composition are prepared by nitrogen sputtering and annealing. The band bending is found to be 0.75+/-0.1 eV up and 0.75+/-0.1 eV down for n- and p-type samples, res pectively. The work function, electron affinity, and Ga 3d core level binding energy are also determined. (C) 1998 American Institute of Phy sics.