| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Nanomaterials | Wednesday Sessions |
| Session NM-WeP |
| Session: | Nanomaterials Poster Session |
| Presenter: | HuiJoon Park, Ajou University, Republic of Korea |
| Correspondent: | Click to Email |
Color filter has been considered as an essential component of various display technologies such as LCDs and OLEDs, because the quality of image and resolution of those displays are significantly affected by the performance of color filters. Existing color filter systems, however, utilize colorant pigments or dyes, whose properties are easily affected by numerous factors including constant UV illumination, longstanding heat exposure and moisture, thus causing the performance degradation of display devices in a relatively short period of time. Furthermore, their low stability with respect to diverse processing chemicals and complicated patterning processes for creating individual pixels are also the biggest concern of the traditional color filter systems.
As an alternative to the present color-generating systems, a structural color filter scheme, which exploits a physical interaction of light with nano- and micro-structures (e.g. photonic and plasmonic resonances), has been widely investigated due to their potential advantages such as ultra-compactness, long-standing stability and simple manufacturability as compared to the conventional color filters.
Particularly, with the growing popularity of high-definition devices, the ability of attaining high spatial resolution by tightly localizing the light energy into neighboring gaps at the deep subwavelength scale, thus being able to create color pixels beyond the diffraction limit, has been another key feature of the structural color filter system. Therefore, in recent years, with the rapid developments of large-scale nanofabrication techniques such as nanoimprint lithography, colloidal self-assembly and laser interference lithography, substantial amount of attention has been given to the various nanostructure-based color filtering systems, which could provide unique and distinct possibilities for enabling a color printing with sub-diffraction resolution. However, there have been great difficulties in retaining optical resonances at the same wavelength over a wide angular range and simultaneously creating vivid full colors in a pixel unit through a one-step process.
Here, an angle-insensitive structural color filtering scheme based on strong interference effects in ultrathin subwavelength semiconductor gratings on metallic substrates is introduced. The proposed color filter devices, which are fabricated over a large area using nanoimprint lithography, produce distinctive colors that are easily tuned by altering a width of the nanostructured gratings even with the fixed thickness of the structure, thus allowing all the individual color pixels to be patterned via one-step fabrication.