The effect of preparation conditions on the structural and optical properties of silicon nanoparticles is investigated. Nanoscale reconstructions, unique to curved nanosurfaces, are presented for silicon nanocrystals and shown to have lower energy and larger optical gaps than bulk-derived structures. We find that high-temperature synthesis processes can produce metastable noncrystalline nanostructures with different core structures than bulk-derived crystalline clusters. The type of core structure that forms from a given synthesis process may depend on the passivation mechanism and time scale. The effect of oxygen on the optical of different types of silicon structures is calculated. In contrast to the behavior of bulklike nanostructures, for noncrystalline and reconstructed crystalline structures surface oxygen atoms do not decrease the gap. In some cases, the presence of oxygen atoms at the nanocluster surface can significantly increase the optical absorption gap, due to decreased angular distortion of the silicon bonds. The relationship between strain and the optical gap in silicon nanoclusters is discussed.

1.
M. F.
Jarrold
and
J. E.
Bower
,
J. Chem. Phys.
96
,
9180
(
1992
).
2.
E. C.
Honea
et al.,
Nature (London)
366
,
42
(
1993
).
3.
U.
Röthlisberger
,
W.
Andreoni
, and
M.
Parrinello
,
Phys. Rev. Lett.
72
,
665
(
1994
).
4.
A. D.
Yoffe
,
Adv. Phys.
50
,
1
(
2001
).
5.
F. A.
Reboredo
,
A.
Franceschetti
, and
A.
Zunger
,
Appl. Phys. Lett.
99
,
2972
(
1999
).
6.
L.
Mitas
et al.,
Appl. Phys. Lett.
78
,
1918
(
2001
).
7.
A.
Puzder
et al.,
Phys. Rev. Lett.
91
,
157405
(
2003
).
8.
E. W.
Draeger
et al.,
Phys. Rev. Lett.
90
,
167402
(
2003
).
9.
G.
Allan
,
C.
Delerue
, and
M.
Lannoo
,
Phys. Rev. Lett.
78
,
3161
(
1997
).
10.
D. J.
Lockwood
et al.,
Solid State Commun.
89
,
587
(
1994
).
11.
L. T.
Canham
,
Appl. Phys. Lett.
57
,
1046
(
1990
).
12.
T.
van Buuren
et al.,
Phys. Rev. Lett.
80
,
3803
(
1998
).
13.
J. P.
Wilcoxon
et al.,
Phys. Rev. B
60
,
2704
(
1999
).
14.
L. N.
Dinh
et al.,
Phys. Rev. B
59
,
15
513
(
1999
).
15.
C.-S.
Yang
et al.,
J. Am. Chem. Soc.
121
,
5191
(
1999
).
16.
J. D.
Holmes
et al.,
J. Am. Chem. Soc.
123
,
3743
(
2001
).
17.
G.
Belomoin
et al.,
Appl. Phys. Lett.
80
,
841
(
2002
).
18.
F. Gygi, computer code GP, version 1.16.0 User’s Manual, LLNL, 2003.
19.
D. R.
Hamann
,
Phys. Rev. B
40
,
2980
(
1989
).
20.
P. Giannozzi (private communication).
21.
R. J. Needs et al., computer code CASINO, version 1.5.4 User’s Manual, University of Cambridge, 2002.
22.
A.
Williamson
et al.,
Phys. Rev. Lett.
89
,
196803
(
2002
).
23.
L. W.
Wang
and
A.
Zunger
,
J. Phys. Chem.
98
,
2158
(
1994
).
24.
M.
Rohlfing
and
S. G.
Louie
,
Phys. Rev. Lett.
80
,
3320
(
1998
).
25.
I.
Vasiliev
,
S.
Ogut
, and
J. R.
Chelikowsky
,
Phys. Rev. Lett.
86
,
1813
(
2001
).
26.
A.
Puzder
et al.,
Phys. Rev. Lett.
88
,
097401
(
2002
).
27.
Z.
Zhou
et al.,
J. Am. Chem. Soc.
125
,
15
599
(
2003
).
28.
L.
Patrone
et al.,
J. Appl. Phys.
87
,
3829
(
2000
).
29.
A.
Puzder
et al.,
J. Am. Chem. Soc.
125
,
2786
(
2003
).
30.
M. V.
Wolkin
et al.,
Phys. Rev. Lett.
82
,
197
(
1999
).
31.
I.
Vasiliev
,
R. M.
Martin
, and
J. R.
Chelikowsky
,
Phys. Rev. B
65
,
121302
(
2002
).
32.
A.
Puzder
et al.,
J. Chem. Phys.
117
,
6721
(
2002
).
This content is only available via PDF.
You do not currently have access to this content.