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Oxygen uptake on an epitaxial PbSnTe(111) surface

1978; American Institute of Physics; Volume: 15; Issue: 4 Linguagem: Inglês

10.1116/1.569756

2331-1754

Tairen Sun, S. Büchner, N. E. Byer, J. M. Chen,

Semiconductor Quantum Structures and Devices

The oxygen uptake of a molecular-beam-epitaxial Pb0.8Sn0.2Te(111) surface has been investigated by AES, XPS, and UPS studies. The results indicate a strong affiliation of oxygen with Sn ions. Oxidation of Sn starts at an exposure of 104 L, whereas oxidation of Pb and Te starts at an exposure of 106 L. Evidence indicates that Sn ions diffuse from the bulk to the surface in the process of oxygen chemisorption. A sharp increase of oxygen uptake is observed at an exposure of 106 L. It marks the commencement of the oxidation process in which bonds between the surface constituents break in favor of individual affiliation with oxygen. A comparison of these results with those previously obtained for PbTe will be discussed.