For the colloidal nanophotonic structures, a transmission electron microscope (TEM) grid has been widely used as a substrate of dark-field microscopy because a nanometer-scale feature can be effectively determined by TEM imaging following dark-field microscopic studies. However, an optically lossy carbon layer has been implemented in conventional TEM grids. A broadband scattering from the edges of the TEM grid further restricted an accessible signal-to-noise ratio. Herein, we demonstrate that the freely suspended, ultrathin, and wide-scale transparent nanomembrane can address such challenges. We developed a 1 mm by 600 μm scale and 20 nm thick poly(vinyl formal) nanomembrane, whose area is around 180 times wider than a conventional TEM grid, so that the possible broadband scattering at the edges of the grid was effectively excluded. Also, such nanomembranes can be formed without the assistance of carbon support; allowing us to achieve the highest signal-to-background ratio of scattering among other substrates.
Bibliographical noteFunding Information:
This work was supported by NRF-2022M3H4A1A02074314 (future technology laboratory program) funded by the National Research Foundation of Korea, the KU-KIST School Project, and a Korea University grant. This work was also supported by the Basic Research Project (Grant No. 401C2905) funded by Korea Electronics Technology Institute. Y.C. is personally supported by the government scholarship funded by the National Research Foundation of Korea (NRF-2018-Global Ph.D. Fellowship Program).
© 2023 American Chemical Society.
- Dark-field spectroscopy
- Mie scattering
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering