Ionization energies and structures of lithium doped silicon clusters

被引:23
作者
De Haeck, Jorg [1 ]
Bhattacharyya, Soumen [1 ]
Hai Thuy Le [1 ]
Debruyne, David [1 ]
Nguyen Minh Tam [2 ,3 ]
Vu Thi Ngan [2 ]
Janssens, Ewald [1 ]
Minh Tho Nguyen [2 ]
Lievens, Peter [1 ]
机构
[1] Katholieke Univ Leuven, Lab Solid State Phys & Magnetism, B-3001 Louvain, Belgium
[2] Katholieke Univ Leuven, Dept Chem, B-3001 Louvain, Belgium
[3] Inst Computat Sci & Technol, Ho Chi Minh City, Vietnam
基金
比利时弗兰德研究基金会;
关键词
ELECTRONIC SHELL STRUCTURE; SODIUM BINARY CLUSTERS; AB-INITIO; SI-N; POTENTIALS; PHOTOIONIZATION; ANIONS;
D O I
10.1039/c2cp40465f
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We report on a combined experimental and theoretical study of the ionization energies and structures of small lithium doped silicon clusters, SinLim with n = 5-11 and m = 3-6. Photoionization efficiency curves are measured in the 4.68-6.24 eV range and subsequently compared with calculated values of both vertical and adiabatic ionization energies for the lowest energy isomers obtained using density functional theory at the B3LYP/6-311+G(d) level. The evolution of the cluster geometries and ionization energies is studied as a function of the number of silicon and lithium atoms along the SinLi3 (n = 5-11) and Si8Lim (m = 1-6) series, respectively. For most studied sizes good agreement is found between the experimental and the calculated ionization energies for the lowest-energy isomer. In the SinLi3 (n = 5-11) series, positively charged lithium atoms surround a negatively charged silicon framework and mainly act as electron donors. Upon sequential lithium addition along the Si8Lim (m = 1-6) series, the Si-8 framework deforms from a rhombic (m = 0, 1) over a tetracapped tetragon (m = 1-4) to a square antiprism (m = 4-6) structure. Subsequent addition of lithium implies the addition of excess electrons to the silicon framework, which is reflected in a decrease of the ionization energy with increasing lithium content. This decrease is non-monotonous and odd-even alternations, reflecting the higher stability of clusters with an even number of electrons, are observed. In addition, post-threshold features in the experimental photoionization efficiency curves of SinLi3 (n = 8-11) may be related to the computed density of states of the corresponding lowest energy isomers.
引用
收藏
页码:8542 / 8550
页数:9
相关论文
共 41 条
[1]   Ionization potential of Al6 and Al7 as a function of temperature [J].
Akola, J ;
Häkkinen, H ;
Manninen, M .
EUROPEAN PHYSICAL JOURNAL D, 1999, 9 (1-4) :179-182
[2]   DENSITY-FUNCTIONAL EXCHANGE-ENERGY APPROXIMATION WITH CORRECT ASYMPTOTIC-BEHAVIOR [J].
BECKE, AD .
PHYSICAL REVIEW A, 1988, 38 (06) :3098-3100
[3]   OBSERVATION OF ELECTRONIC SHELL STRUCTURE IN LARGE CESIUM OXIDE CLUSTERS [J].
BERGMANN, T ;
MARTIN, TP .
JOURNAL OF CHEMICAL PHYSICS, 1989, 90 (06) :2848-2855
[4]   Production of bimetallic clusters by a dual-target dual-laser vaporization source [J].
Bouwen, W ;
Thoen, P ;
Vanhoutte, F ;
Bouckaert, S ;
Despa, F ;
Weidele, H ;
Silverans, RE ;
Lievens, P .
REVIEW OF SCIENTIFIC INSTRUMENTS, 2000, 71 (01) :54-58
[5]   Structural Identification of Caged Vanadium Doped Silicon Clusters [J].
Claes, P. ;
Janssens, E. ;
Ngan, V. T. ;
Gruene, P. ;
Lyon, J. T. ;
Harding, D. J. ;
Fielicke, A. ;
Nguyen, M. T. ;
Lievens, P. .
PHYSICAL REVIEW LETTERS, 2011, 107 (17)
[6]   Vibrational spectroscopy of neutral silicon clusters via far-IR-VUV two color ionization [J].
Fielicke, Andre ;
Lyon, Jonathan T. ;
Haertelt, Marko ;
Meijer, Gerard ;
Claes, Pieterjan ;
de Haeck, Jorg ;
Lievens, Peter .
JOURNAL OF CHEMICAL PHYSICS, 2009, 131 (17)
[7]  
Frisch M., 2004, GAUSSIAN 03 REVISION, DOI DOI 10.1016/J.MOLSTRUC.2017.03.014
[8]   NEAR-THRESHOLD PHOTOIONIZATION OF SILICON CLUSTERS IN THE 248-146 NM REGION - IONIZATION-POTENTIALS FOR SI(N) [J].
FUKE, K ;
TSUKAMOTO, K ;
MISAIZU, F ;
SANEKATA, M .
JOURNAL OF CHEMICAL PHYSICS, 1993, 99 (10) :7807-7812
[9]   The role of adsorbed alkali metal atoms in the enhancement of surface reactivity: A scanning tunneling microscopy study of low coverage K/Si(111)7x7 surfaces [J].
Gorelik, D ;
Aloni, S ;
Eitle, J ;
Meyler, D ;
Haase, G .
JOURNAL OF CHEMICAL PHYSICS, 1998, 108 (23) :9877-9884
[10]   INTERPRETATION OF PHOTOIONIZATION THRESHOLD BEHAVIOR [J].
GUYON, PM ;
BERKOWIT.J .
JOURNAL OF CHEMICAL PHYSICS, 1971, 54 (04) :1814-&