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The initial growth of Se100-xTex alloy (with the composition of x=0,30,50,80 and 100at%) films deposited on Au(111) surfaces at 298K have been studied by Auger electron spectroscopy (AES) and low-energy electron diffraction (LEED). The Au(111) surfaces were formed by vacuum deposition on air-cleaved MoS2 at 590K. After cool down the substrate temperature, Se100-xTex alloy was deposited in situ on the Au(111) surfaces.
In the cases of Se and Se70Te30 films, LEED results show that (√3 × √3)R30°structure appears at 1 monolayer(ML), and that the overlayers are rearranged with the (1 × √7)R79.1°structure up to 3ML. For further deposition, no extra LEED spots are observed. AES result predicts that after 1ML of Se films is completed in layer-by-layer growth mode, island growth begins. Also, AES result predicts that after 1ML of Se70Te30 films is completed in layer-by-layer growth mode, simultaneous multilayer (SM) growth begins. In the case of Se50Te50 films, AES result predicts that after 1ML of Se50Te50 films is completed in SM growth mode, island growth begins. LEED result of Se50Te50 overlayers are similar to that of Se films. In the case of Se20Te80 films, the overlayer grows in island growth mode. The Se20Te80 overlayer corresponding to 1ML shows incommensurate (√3 × √3)R30°structure. For further Se20Te80 deposition, no extra LEED spots observed. In the case of Te films, AES result predicts that Te grows in island growth mode. Te overlayer corresponding to 1ML shows incommensurate (√3 × √3)R30°structure. For further Te deposition, (3 × 3) structure and complex structure are observed up to 3ML.
These results suggest that when the composition x increases, the 1ML growth of Se100-xTex overlayer is shifted from layer-like growth towards island-like growth.
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