Fabrication and Unique Optical Properties of Two-Dimensional Silver Nanorod Arrays with Nanometer Gaps on a Silicon Substrate from a Self-Assembled Template of Diblock Copolymer.
A periodic array of nanoholes was fabricated via the self-assembly of a polystyrene(PS)-b-poly(methyl methacrylate) (PMMA) block copolymer (BCP) on a silicon substrate and selective etching of the PMMA moieties. Silver nanorods (AgNRs) were then selectively deposited in the nanoholes by a galvanic displacement reaction where the pattern was hexagonally aligned according to the template. The diameter of AgNRs was controlled by changing the immersion time. Optical measurements of the AgNR arrays revealed that the extinction peak was split into two because of the electromagnetically induced transparency effect. In addition, the AgNR arrays showed a surface-enhanced Raman scattering response and were successfully transferred from a silicon substrate to a transparent and flexible polymer film while retaining the rod arrangement.
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University , 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.|Center for Molecular Systems, Kyushu University , 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.|Interfacial Nanostructure Laboratory, RIKEN , Wako, Saitama 351-0198, Japan.
Shigenori
S
Fujikawa
Interfacial Nanostructure Laboratory, RIKEN , Wako, Saitama 351-0198, Japan.
Mari
M
Koizumi
Interfacial Nanostructure Laboratory, RIKEN , Wako, Saitama 351-0198, Japan.
Akiko
A
Taino
Institute for Materials Chemistry and Engineering, Kyushu University , 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
Koichi
K
Okamoto