矽單層在銀/矽(111)-(1x1)薄膜表面上的成長

Abstract

在本實驗中我們利用液態氮將 Si (111)-7×7 基板降至100 K後，再用K-cell 蒸鍍銀原子於表面，經過熱退火後得到平整的銀薄膜。 在該薄膜上我們維持一定的溫度蒸鍍矽原子，藉此成長矽單層。在改變不同溫度下蒸鍍矽原子，我們透過掃描穿隧式顯微鏡發現4種不同結構的矽單層，包括4×4、√13×√13-1、√13×√13-2、2√3×2√3，並且發現 4×4 結構在高溫比較容易出現。而在超過 1 ML 的鍍量實驗中我們發現第二層的矽單層和 2×2 的有序排列。 另外，從低能量電子繞射儀的觀察，發現銀薄膜表面原子排列存在錯位，在這種表面成長矽單層會使得排列方向改變。在排列方向改變的區域存在明顯的邊界或是排列的空缺。

After depositing silver on Si (111)-(7×7) by k-cell at 100K and annealing the substrate to 300℃，we got the flatten silver films on silicon substrate. We grow silicene on these silver films at different temperature and found four different types of silicene including 4×4、√13×√13-1、√13×√13-2、2√3×2√3 structure by using scanning tunneling microscope . We found that at higher depositing temperature the rate of 4×4 structure would increase .When we deposit more than 1 ML Si atoms，part of Si atoms will form second layer silicene and 2×2 arrangement. On the other hand，we found that silver films have dislocations by low energy electron diffraction. Dislocations cause the change of silicene arrangement .The region of arrangement change have obvious boundary or spots absence .