Abstract
Hydrogen sensor technologies have been rapidly developing. For effective and safe sensing, we proposed a hydrogen sensor composed of magnesium (Mg), silver (Ag), and palladium (Pd) nano-blocks that overcomes the spectral resolution limit. This sensor exploited the properties of Mg and Pd when absorbing hydrogen. Mg became a dielectric material, and the atomic lattice of Pd expanded. These properties led to changes in the plasmonic gap mode between the nano-blocks. Owing to the changing gap mode, the far-field scattering pattern significantly changed with the hydrogen concentration. Thus, sensing the hydrogen concentration was able to be achieved simply by detecting the far-field intensity at a certain angle for incident light with a specific wavelength.