Perfect absorber design and analysis with metamaterial-based plasmonic nanoantennas

Today, the interest and financial support devoted to this subject by R&D studies and research centers in the field of nanotechnology is increasing. When a short literature review is made, it is seen that researches on spectroscopy methods such as surface-enhanced Raman spectroscopy (SERS), infrared absorption spectroscopy (SEIRA), nanoantennas and excellent absorbers have been made and researches continue. The engineering of plasmonic nanostructures has recently established a strong basis for biosensing via surface-assisted sensing and has spurred new applications in molecular studies. In particular, SEIRA with engineered plasmonic nanostructures has the unique ability to detect different infrared vibrational traces of a thin layer of molecules by far-field measurements. Metamaterials are artificial materials that are not found in nature. When nano-sized materials are obtained artificially, they can be considered as metamaterials. Examples of these are metals such as gold, silver, aluminium used in nanoantennas. Silver is where it exhibits the lowest losses of current materials at both visible, near infrared, and other wavelengths. Aluminium has little advantage at visible wavelengths. Gold performs equally well in visible and near-infrared. Aluminium has the advantage over both silver and gold that it is chemically stable in natural environments, making it well-suited for plasmonic biosensors. However, an interband transition at ~470 nm greatly increases losses at wavelengths below 600 nm. Aluminium is the best plasmonic material in the ultraviolet regime (< 330 nm). Each biosensor-based nanoantenna has properties such as selectivity, repeatability, stability, sensitivity, and linearity. In this thesis study, "Perfect Absorber Design and Analysis with Metamaterial Based Plasmonic Nanoantennas" was carried out by using 3 different conductors (Gold, Silver and Aluminium) and 3 different dielectric (SiO2, MgF2 and AlO2) materials, considering these properties. In the first introductory part of the thesis, brief information about different chemical analysis samples is given and analysis examples are given along with the aims of the studies. The general properties of the metals used were given, the excellent absorbers were compared with each other and the detectability of the 3 nanoantennas with the best absorption and DNT and PMMA molecules were revealed. As a result of the experiments, it has been observed that when the right and left lengths of the bar (patch) are increased in the nanoantenna using gold and silver, the absorption increases, and the absorption decreases in nanoantennas using aluminium. As a result, the best absorption was found in the MIM (Metal Insulator Metal) nanoantenna structure in AlSiO2AL (Aluminium Silica) structure and the designed antennas were deemed suitable for infrared spectroscopy. It is thought that the thesis study can give direction to future studies.