Element substitution from substrates in Bi₂Se₃, Bi₂Te₃and Sb₂Te₃overlayers deposited by hot wall epitaxy

Abstract

In depositing Bi 2 Se 3 , Bi 2 Te 3 or Sb 2 Te 3 layers on certain substrates by hot wall epitaxy, the Bi and Sb atoms in the layers are replaced by the atoms supplied from the substrates. We extend our exploration on this substitution phenomenon for a number of combinations of the layer and the substrate to infer the factors that determine the occurrence of the substitution. Using a series of Ga-and In-based III-V substrates, it is evidenced that the group III atoms substitute the group V overlayer atoms when the bonds in the substrates are weak. We demonstrate that Ag triggers the substitution more effectively than Cu as a catalyst. The competition between the catalyst-induced substitutions on ternary alloy substrates shows that the dependence on the bond strength is not as strong as to be exclusive. Additionally, defectiveness around the interface between a semicoherently grown α-In 2 Se 3 layer produced by the substitution and the InAs substrate is demonstrated. The cathodeluminescence properties are also provided focusing on the dependence on the phase of In 2 Se 3 .

Memristive resistive switch based on spontaneous barrier creation in metal-chalcogenide junctions

“…The chalcogenide film that we employ in the present work was produced by material substitution that occurred when Bi 2 S 3 was deposited by hot wall epitaxy on a Cu film [12][13][14][15][16]. The epitaxy was carried out by placing polycrystalline Bi 2 S 3 pieces and a Cu-coated Si(0 0 1) substrate in an evacuated quartz tube with a distance of about 30 cm from each other.…”