High-temperature indium adsorption on Bi2Se3(0001) surface studied by in situ reflection electron microscopy.

• Impurity-induced 2D phase forms on Bi 2 Se 3 surface during submonolayer In deposition. • Islands of indium-induced surface phase have a height of 0.4 nm. • During indium deposition, area of the surface phase increases until complete coverage. • The phase locally suppresses sublimation, which creates multilayer star-shaped islands. Using in situ reflection electron microscopy, transformations of Bi 2 Se 3 (0001) surface during In deposition have been studied. We first report the formation of an In-induced surface phase that precedes nucleation and growth of a layered In 2 Se 3 at substrate temperatures around 400 °C. The surface phase nucleates on Bi 2 Se 3 (0001) terraces as islands having high In content and a height of 0.4 nm. During continuous In deposition, the area of these islands increases and suppresses Bi 2 Se 3 sublimation from the regions covered by the In-induced surface phase. This locally suppressed sublimation and sublimation-induced ascending motion of Bi 2 Se 3 atomic steps create multilayer triangular star-shaped islands. [ABSTRACT FROM AUTHOR]