Investigation of the physical properties of (C20)2P AND (C20P)2 molecules by simulation methods

Nanotechnology represents a field of science that enables precise control over matter at the atomic and molecular level. By examining the properties and behaviors of materials at the nanometer scale, nanotechnology has made it possible to produce new devices and systems that can be used for various applications, thus creating new opportunities across many fields. Nanosensors, one of the most significant and exciting applications of nanotechnology, are devices made of nanometer-scale materials that can detect various biological, physical or chemical parameters with precision and convert them into electrical, optical or mechanical signals. In this thesis, initially, the historical development of nanotechnology and its fundamental concepts, including the classification, properties, applications and advancements of nanosensors, are examined in detail. In addition, the structural and electronic properties of the (C20)2P and (C20P)2 molecules were calculated using Density Functional Theory (DFT). In the calculations, the binding energies for the optimized (C20)2P and (C20P)2 structures were obtained as -41.06 eV and -21.78 eV, respectively. In the (C20)2P molecule, it was observed that the inserted phosphorus atom altered the structure of one of the fullerenes, transforming the C20 framework, originally composed of twelve pentagons, into a structure consisting of ten pentagons and two hexagons. In the (C20P)2 molecule, it has been observed that the P – P bond between the phosphorus atoms has ruptured. As a result of this, it has been found that each phosphorus atom forms a bond with one of the carbon atoms in the fullerenes, resulting in the formation of a hexagonal structure. In this case, no alterations were observed in the pentagons of the fullerenes. The calculated GapHL values for the (C20)2P and (C20P)2 structures are 0.83 eV and 1.33 eV, respectively, indicating that they can be considered as semiconducting materials.