The time-dependent process of oxidation of the surface of Bi₂Te₃studied by x-ray photoelectron spectroscopy

Abstract

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 Bi 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 (t-t0)1/2 when d(t) was smaller than the thickness of a single oxidized quintuple atomic layer in our oxide model and behaved as t-t1 when it was larger than that. Experimental data were compared to our oxidation process model for the layered structure with the van der Waals gap and very good agreement was found.

In situspectroscopy of intrinsicBi2Te3topological insulator thin films and impact of extrinsic defects

“…The UHV conditions of this system ensure that films are free from ex situ contamination. [18,23,24].…”

Reduced thermal conductivity by nanoscale intergrowths in perovskite like layered structure La2Ti2O7

“…Most of these materials have zT close to unity, but they are not stable in air due to the oxidation at these temperatures. 10 Oxide materials are inexpensive, abundant in nature, non-toxic, and environmentally friendly. These materials possess high chemical and thermal stability which makes them suitable for high temperature thermoelectric application in air.…”

Inertness and degradation of (0001) surface of Bi2Se3 topological insulator

“…It was shown that the surface electronic properties of the three-dimensional topological insulators (TIs) were affected by the surface adsorption of residual gases, 2 air, 3 CO, 4 H 2 O, 5 and oxygen. 7,8 In particular, the air exposure over several hours apparently causes the surface oxidation and environmental doping. [6][7][8] It was demonstrated that oxidation of Bi 2 Se 3 results in a complex band structure because of hybridization of the O-derived states with the substrate states.…”

“…7,8 In particular, the air exposure over several hours apparently causes the surface oxidation and environmental doping. [6][7][8] It was demonstrated that oxidation of Bi 2 Se 3 results in a complex band structure because of hybridization of the O-derived states with the substrate states. 9 The formation of intrinsic oxides observed on the (0001) Bi 2 Se 3 and Bi 2 Te 3 surfaces can be responsible for the change of sign in surface conductivity with time 10 and even for deterioration of the topological surface states properties 7 as well as for reduction of the spin current.…”