We investigate light absorption in metal films, silver and aluminum, with different surface roughness. Measurements using an integrating sphere show that the reflectance in silver decreases significantly with increasing surface roughness whereas the reflectance in aluminum is almost constant. The experimental results agree well with numerical simulations in which the surface roughness of metal is described properly. In particular, the simulations demonstrate that the absorption by surface-plasmon-polaritons excited on a rough silver surface causes the surface-dependent reflectance in silver. This study suggests a convenient and feasible rule to rationally design a backside metal reflector toward high-efficiency light-emitting diodes and photovoltaics.

1.
M. P.
Nezhad
,
A.
Simic
,
O.
Bondarenko
,
B.
Slutsky
,
A.
Mizrahi
,
L.
Feng
,
V.
Lomakin
, and
Y.
Fainman
,
Nat. Photonics
4
,
395
(
2010
).
2.
J. J.
Wierer
,
A.
David
, and
M. M.
Mergens
,
Nat. Photonics
3
,
163
(
2009
).
3.
S. -K.
Kim
,
J. W.
Lee
,
H. -S.
Ee
,
Y. -T.
Moon
,
S. -H.
Kwon
,
H.
Kwon
, and
H. -G.
Park
,
Opt. Express
18
,
11025
(
2010
).
4.
M. D.
Kelzenberg
,
S. W.
Boettcher
,
J. A.
Petykiewicz
,
D. B.
Turner-Evans
,
M. C.
Putnam
,
E. L.
Warren
,
J. M.
Spurgeon
,
R. M.
Briggs
,
N. S.
Lewis
, and
H. A.
Atwater
,
Nature Mater.
9
,
239
(
2010
).
5.
W. H.
Koo
,
S. M.
Jeong
,
F.
Araoka
,
K.
Ishikawa
,
S.
Nishimura
,
T.
Toyooka
, and
H.
Takezoe
,
Nat. Photonics
4
,
222
(
2010
).
6.
R. A.
Pala
,
J.
White
,
E.
Barnard
,
J.
Liu
, and
M. L.
Brongersma
,
Adv. Mater.
21
,
3504
(
2009
).
7.
V. E.
Ferry
,
L. A.
Sweatlock
,
D.
Pacifici
, and
H. A.
Atwater
,
Nano Lett.
8
,
4391
(
2008
).
8.
P.
Nagpal
,
N. C.
Lindquist
,
S. -H.
Oh
, and
D. J.
Norris
,
Science
325
,
594
(
2009
).
9.
S. -H.
Kwon
,
J. -H.
Kang
,
C.
Seassal
,
S. -K.
Kim
,
P.
Regreny
,
Y. -H.
Lee
,
C. M.
Lieber
, and
H. -G.
Park
,
Nano Lett.
10
,
3679
(
2010
).
10.
M.
Born
and
E.
Wolf
,
Principles of Optics
, 7th ed. (
Cambridge University Press
,
Norwood
,
1999
).
11.
S. A.
Maier
and
H. A.
Atwater
,
J. Appl. Phys.
98
,
011101
(
2005
).
12.
D. K.
Gramotnev
and
S. I.
Bozhevolnyi
,
Nat. Photonics
4
,
83
(
2010
).
13.
A.
Taflove
and
S. C.
Hagness
,
Computational Electrodynamics: The Finite-Difference Time-Domain Method
, 3rd ed. (
Artech House
,
Norwood, MA
,
2005
).
14.
P. B.
Johnson
and
R. W.
Christy
,
Phys. Rev. B
6
,
4370
(
1972
).
15.
D. R.
Lide
,
CRC Handbook of Chemistry and Physics
, 87th ed. (Internet Version 2007,
Taylor & Francis
,
Boca Raton, FL
,
2007
).
16.
K.
Okamoto
,
I.
Niki
,
A.
Shvartser
,
Y.
Narukawa
,
T.
Mukai
, and
A.
Scherer
,
Nature Mater.
3
,
601
(
2004
).
17.
A.
Bagchi
,
C. B.
Duke
,
P. J.
Feibelman
, and
J. O.
Porteus
,
Phys. Rev. Lett.
27
,
998
(
1971
).
18.
H. K.
Cho
,
J.
Jang
,
J. -H.
Choi
,
J.
Choi
,
J.
Kim
,
J. S.
Lee
,
B.
Lee
,
Y. H.
Choe
,
K. -D.
Lee
,
S. H.
Kim
,
K.
Lee
,
S. -K.
Kim
, and
Y. -H.
Lee
,
Opt. Express
14
,
8654
(
2006
).
You do not currently have access to this content.