摘要
研究—Ｈ，—Ｏ或—ＯＨ基吸附于表面的纳米硅集团电子结构的变化情况．选取了几种可能的吸附构型，用定域密度泛函（ＬＤＦ）集团模型数值自洽求解方法的第一性原理计算，求得优化的吸附位置、相应的电子结构，并分析了有关的光学性质．在全氢饱和的情况下，能隙比硅体的宽，呈明显的量子尺寸效应；部分—Ｈ被—Ｏ原子取代后，在禁带中出现一些“尾态”，这些态部分被占有；若以—ＯＨ基取代—Ｏ，则相应的空尾态被占有，但带隙变化不大．
The electronic structures of H,O and OH chemisorbed on Si nano clusters were calculated with local density functional formalism. Atomic force calculations were used to reach at an optimized chemisorption site for the adsorbates. Different models were used. For all H adsorbed clusters, wider energy gaps are opened up compared with that of bulk Si, and quantum size effect is obviously shown. When a shell of the adsorbed H atoms is replaced by oxygen atoms, oxygen induced tail states appear in the gap. Both occupied and unoccupied states exist, and the gap is reduced from that in all H terminated cases. For O atoms replaced by OH, the tail states become all occupied, but the gap widths do not differ much. No quantum size effects are observable for both O and OH adsorption.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1996年第11期1890-1897,共8页
Acta Physica Sinica
