The time-dependent process of oxidation of the surface of Bi2Te3 studied by x-ray photoelectron spectroscopy

The process of oxidation of the Bi2Te3 surface was investigated by x-ray photoelectron spectroscopy (XPS). The oxidized surface layer was found to have a definite thickness, with configurations where O is bonded with Pi and Te, and Bi and Te are bonded with three and four oxygens, respectively The oxidation time dependence of the oxidized layer thickness d(t) estimated from the XPS behaved as root t - t(0) when d(t) was smaller than the thickness of a single oxidized quintuple atomic layer in our oxide model and behaved as t - t(1) when it was larger than that. Experimental data were compared to our oxidation process model for me layered structure with the van der Waals gap and very good agreement was found.