| AVS 62nd International Symposium & Exhibition | |
| Thin Film | Monday Sessions |
| Session TF+AS+SS-MoM |
| Session: | Self-Assembled Monolayers, Layer-by-Layer, etc. |
| Presenter: | Midori Kawamura, Kitami Institute of Technology, Japan |
| Authors: | M. Kawamura, Kitami Institute of Technology, Japan C. Kudo, Kitami Institute of Technology T. Sasaki, Kitami Institute of Technology Y. Abe, Kitami Institute of Technology K.H. Kim, Kitami Institute of Technology T. Kiba, Kitami Institute of Technology |
| Correspondent: | Click to Email |
Due to excellent physical properties, Ag thin films have been used as low-e coating, optical mirror, and so on. It is necessary to prevent degradation of the Ag films in air or humid atmosphere. For the purposes, it has been reported that several metal oxide nanolayers and organic monolayers are effective to make Ag thin films stable. Previously, we reported that modification of Ag films with 3-mercaptopropyltrimethoxysilane (MPTMS) monolayer can improve durability of the Ag films after environmental tests because strong bonds were formed between thiol moiety and Ag films, and also between silanol moiety and glass substrate. In the present study, we attempted to use other type of organic molecules, namely straight chain alkylthiols, such as 1-octadecanthiol (1-ODT), 1-dodecanthiol (1-DT) for protection of Ag film surface and compared with MPTMS.
Ag thin films (10nm) were deposited on clean glass substrates by vacuum evaporation. Then monolayer of 1-ODT and 1-DT were formed over the Ag thin films by solution method. The samples were kept in a constant temperature and humidity chamber (40 degree Celsius and 90 RH%) for a week. The electrical resistance, surface morphology, optical transmittance were measured before and after the test. Ag film without the monolayer, and that with MPTMS were also examined for comparison.
The surface roughness of the Ag film without the monolayer drastically increased from 2.7 nm to 27 nm after the test. However, the increase was within 1nm on Ag films with 1-DT and 1-ODT surface layers. These changes were smaller than that on Ag film with MPTMS surface layer. By the measurement of electrical resistivity, it was found that increase in the resistivity after the test was very much suppressed in the Ag film with these monolayers. In addition, optical transmittance measurement showed that transmittance spectrum of Ag films with these monolayers did not change after the test. These results accord with the Ag film morphology change. Consequently, excellent passivation effect of 1-DT and I-ODT surface monolayers on Ag films was confirmed.