Thickness induced metal-nonmetal transition in ultrathin electrodeposited Ge films

被引:19
作者
Mukhopadhyay, I [1 ]
Freyland, W [1 ]
机构
[1] Univ Karlsruhe TH, Inst Phys Chem, D-76128 Karlsruhe, Germany
关键词
D O I
10.1016/S0009-2614(03)01098-4
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
Elemental Ge has been electrodeposited from 35 mM GeCl4 solution in 1-butyl-3-methyl imidazolium hexafluoro phosphate ([BMIm]PF6) on Si(1 1 1):H substrate at room temperature and studied by in situ electrochemical scanning tunneling microscopy (EC-STM) and scanning tunneling spectroscopy (STS). The initial stage of electrodeposition showed roughening of the surface with amorphous deposits all over the substrate. An ordered (2 x n) reconstruction was found to form in the 1-2 ML coverage regime. The remarkable observation, which is reported here for the first time is a metal-to-nonmetal transition as the thickness of the deposited Ge layer on Si(I I 1):H increased from 2 ML to about 3 nm. (C) 2003 Elsevier B.V. All rights reserved.
引用
收藏
页码:223 / 228
页数:6
相关论文
共 11 条
[1]   The preparation of flat H-Si(111) surfaces in 40% NH4F revisited [J].
Allongue, P ;
de Villeneuve, CH ;
Morin, S ;
Boukherroub, R ;
Wayner, DDM .
ELECTROCHIMICA ACTA, 2000, 45 (28) :4591-4598
[2]   Electronic density of empty states of Ge/Si(111) epitaxial layers: Theory and experiment [J].
Castrucci, P ;
Gunnella, R ;
De Crescenzi, M ;
Sacchi, M ;
Dufour, G ;
Rochet, F .
PHYSICAL REVIEW B, 1999, 60 (08) :5759-5769
[3]   Investigation of Ge on Si(100) quantum wells by photoelectron spectroscopies [J].
Di Gaspare, L ;
Capellini, G ;
Cianci, E ;
Evangelisti, F .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, 1998, 16 (03) :1721-1724
[4]  
DUKE CB, 2002, FRONTIER SURFACE INT, P56118
[5]  
FREYLAND W, 2003, UNPUB ELECTROCHIM AC
[6]  
HOLBREY JD, 1998, J CHEM SOC DA, V13, P2133
[7]   In situ Raman monitoring of ultrathin Ge films [J].
Kanakaraju, S ;
Sood, AK ;
Mohan, S .
JOURNAL OF APPLIED PHYSICS, 1998, 84 (10) :5756-5760
[8]   Effect of strain on structure and morphology of ultrathin Ge films on Si(001) [J].
Liu, F ;
Wu, F ;
Lagally, MG .
CHEMICAL REVIEWS, 1997, 97 (04) :1045-1061
[9]   High temperature electrochemical scanning tunneling microscope instrument [J].
Shkurankov, A ;
Endres, F ;
Freyland, W .
REVIEW OF SCIENTIFIC INSTRUMENTS, 2002, 73 (01) :102-107
[10]   Optical properties of ultrathin films: Evidence for a dielectric anomaly at the insulator-to-metal transition [J].
Tu, JJ ;
Homes, CC ;
Strongin, M .
PHYSICAL REVIEW LETTERS, 2003, 90 (01) :4