锌掺杂硅团簇ZnSi_n(n=2～8)及其氢化物的几何结构和稳定性  

Geometrical Structures and Stabilities of Zinc-Doped Silicon ZnSi_n(n=2～8) Clusters and Their Hydrides

作　　者：李小军 毛俊[2] 任宏江 LI Xiaojun;MAO Jun;REN Hongjiang(School of Science,Xi'an University of Posts and Telecommunications,Xi'an 710121,China;School of Chemical Engineering,Xi'an University,Xi'an 710065,China)

机构地区：[1]西安邮电大学理学院,陕西西安710121 [2]西安文理学院化学工程学院,陕西西安710065

出　　处：《材料科学与工程学报》2019年第5期725-730,735,共7页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(21603173,21643014);陕西省自然科学基金资助项目(2016JQ5110);西安市科技计划资助项目(2016CXWL16,2016CXWL02)

摘　　要：运用杂化密度泛函理论(DFT)方法在B3LYP/6-311+G*水平上,研究了ZnSin(n=2~8)及其氢化HmZnSin(m=1~2,n=2~8)团簇的几何结构和稳定性。通过理论计算,确定了锌掺杂和氢化团簇的基态结构和几种低能异构体。研究结果发现:掺杂ZnSin团簇的大部分结构都是立体构型。当在团簇表面吸附1H和2H时,其结构骨架与ZnSin团簇基本保持一致,同时氢原子优先吸附在团簇表面的硅原子上。平均键能的分析揭示了H1ZnSin团簇具有较高的相对稳定性;根据解离能计算表明,H2ZnSin团簇的脱2H解离能(De4(n)=E(ZnSin)+2E(H)-E(H2ZnSin))最大,说明其在团簇表面吸附2H原子能够提高团簇的化学稳定性。此外,HOMO-LUMO能隙(GAP)计算结果也发现,当3≤n≤6时,计算得到GAP(H2ZnSin)>GAP(H1ZnSin)>GAP(ZnSin),表明H2ZnSin团簇具有较大的HOMO-LUMO能隙,其化学稳定性更高,该结果与H2ZnSin团簇的脱2H解离能相一致。Geometrical structures and stabilities of zinc-doped silicon(ZnSin(n=2~8)) and their hydrogenated(HmZnSin(m=1~2, n=2~8)) clusters were systematically studied using the hybrid density functional theory(DFT) calculations at the B3 LYP/6-311+G* level of the theory. According to the theoretical predictions, the ground-state structures of these clusters and their low-lying isomers are found. The results showed that the stable structures of the ZnSin clusters are almost 3 D configurations. When adsorbing 1 H and 2 H on clusters’ surface, their hydrogenated clusters mainly keep the structural framework of ZnSin clusters, and H atoms are preferred to adsorb on silicon atom. Analysis of averaged binding energy indicates that the H1ZnSin clusters have the high chemical stability, whereas the dissociation energies with the removal of 2 H for the H2ZnSin clusters(De4(n)=E(ZnSin) + 2E(H)-E(H2ZnSin)) are very large, indicating that the adsorption of 2 H on clusters’ surface can improve their chemical stability. In addition, it is also found from HOMO-LUMO gaps(GAP) that the H2ZnSin clusters exist the large energy gaps, and the stable order is GAP(H2ZnSin)>GAP(H1ZnSin)>GAP(ZnSin) when 3≤n≤6, which is consistent with its dissociation energy with the removal of 2 H.

关 键 词：ZnSi_n团簇 氢化团簇 几何结构 化学稳定性 密度泛函理论 

分 类 号：O641[理学—物理化学]