Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1252-1256.doi: 10.3866/PKU.WHXB201202131

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Oxidation and Oxygen Thermal Desorption Mechanism on Narrow-Gap IV-VI Semiconductor PbTe(111) Surface

WU Hai-Fei1, WU Ke2, ZHANG Han-Jie2, LIAO Qing2, HE Pi-Mo2   

  1. 1. Department of Physics, Shaoxing University, Shaoxing 312000, Zhejiang Province, P. R. China;
    2. Department of Physics, Zhejiang University, Hangzhou 310027, P. R. China
  • Received:2011-11-30 Revised:2012-01-20 Published:2012-04-26
  • Contact: HE Pi-Mo
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (60506019, 10674118, 10774129).

Abstract: Oxidation and thermal desorption mechanism on the PbTe(111) surface were investigated using X-ray photoemission spectroscopy (XPS), scanning tunneling microscopy (STM), and low-energyelectron diffraction (LEED). The initial cleaning of the surface by 500 VAr+ sputtering followed by annealing at 250 °C yielded a perfect (1×1) PbTe(111) surface. XPS measurements showed that PbO2, PbO, and TeO2 were present at the PbTe(111) surface after air exposure for 2 days, and the intensity ratio of Te 3d5/2 and Pb 4f7/2 increased rapidly compared to that of the clean PbTe(111) surface, indicating Te depletion and Pb enrichment of the surface. XPS and STM measurements showed that the thickness of the oxide layer was more than 2 monolayers (MLs). During thermal treatment, the core levels of PbO2 and TeO2 disappeared and the intensity of the O 1s core level decreased, indicating surface decomposition of PbO2 and TeO2, and desorption of oxygen, whereas PbO was still present on the surface after annealing at up to 350 °C.

Key words: Surface oxidation, Desorption, PbTe(111), X-ray photoemission spectroscopy, Scanning tunneling microscopy


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