Azot İçeren Borafenalen Temelli Organik Yarı İletken Modellerinin Teorik İncelenmesi

Abstract

Organic semiconductors are the basic building materials of instruments used in many fields including opto-electronics, photo-electronics, thermo-electronics, transistors and solar cells and have an important place in electrochemistry. It is preferred more than its inorganic counterparts due to its low toxicity and low cost production. Semiconductors used in this field are divided into p-type based on hole mobility and n-type based on electron mobility. Although a large number of p-type semiconductors with high conductivity and good environmental stability have been designed and presented, n-type semiconductors have lagged behind their p-type counterparts due to both their environmental stability and the difficulty of synthesizing basic small molecules.

For many years, many methods have been tried to improve the performance of n-type semiconductors. As a result of these researches, to increase the performance of organic semiconductors and the expected properties of a good n-type organic semiconductor should be as follows; high electron affinity, low LUMO (\le\ -4.0 eV) energy value for air-stability, low HOMO energies to suppress hole injection and a planar -conjugated backbone and low conductivity band gaps (~\ 1. 0 eV). In this context, we presented newly designed borafenalene structures in our study.

In this thesis study, borafenal structures have low HOMO/LUMO energies, planar and -conjugated structures, as well as B and N atoms in the basic skeleton unit, HOMO energy has been reduced to the desired level. We were able to prospectively calculate that different side groups and fluorine substituents in our structure reduce the conductivity bandwidth by affecting theelectron-withdrawingg potential of -conjugate bursts both LUMO and HOMO energy dissipation and have very low LUMO values.

The ground state geometries and HOMO/LUMO values of the gas phase and different side groups of the borafenalens in this study were calculated using the DFT (Density Functional Theory) method, B3LYP/6-311++G(d,p) method, and the conductivity band gaps were found. The results of this study will help to overcome the deficiencies in the design and performance of n-type organic semiconductors and will offer new ways.