Doping-Dependent Adsorption and Photon-Stimulated Desorption of CO on GaN(0001)

CO is used as a chemical probe molecule to elucidate the properties of differently n-type doped GaN(0001) surfaces under ultrahigh vacuum conditions. Doping-dependent sticking of CO is observed by temperature-programmed desorption, which is not influenced by the surface composition of the semiconductor substrates. By the excitation of the semiconductor with UV photons a low-temperature desorption of CO is stimulated. The absolute photon-stimulated desorption intensity strongly depends on the surface composition. However, the desorption kinetics do not significantly depend on the surface composition, semiconductor doping, or UV excitation wavelength. A model is introduced, which is based on the electronic characteristics of the GaN substrates and describes the doping-dependent adsorption as well as the photochemical behavior.     «

CO is used as a chemical probe molecule to elucidate the properties of differently n-type doped GaN(0001) surfaces under ultrahigh vacuum conditions. Doping-dependent sticking of CO is observed by temperature-programmed desorption, which is not influenced by the surface composition of the semiconductor substrates. By the excitation of the semiconductor with UV photons a low-temperature desorption of CO is stimulated. The absolute photon-stimulated desorption intensity strongly depends on the sur...     »