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

作者：Kollmann**erger Sebastian L; Walenta Constantin A; Winnerl Andrea; Weiszer Saskia; Pereira Rui N; Tschurl Martin; Stutzmann Martin; Heiz Ueli^*

来源：Journal of Physical Chemistry C, 2017, 121(15): 8473-8479.

DOI：10.1021/acs.jpcc.7b01570

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.

• 出版日期2017-4-20