NEW THIOPHENE BASED MATERIALS FOR EMISSIVE LAYERS OF ORGANIC LIGHT-EMITTING DIODES

Abstract

Optoelectronic display devices have gained an important role in the modern world. Digital displays based on organic light-emitting diodes are taking one of the leading places among other displays due to high contrast and high-quality color gamut. The relative novelty of the technology is the reason for the insufficient number of researched materials for use in layers of organic light-emitting diodes. This paper analyzes the properties of molecular structures based on thiophene heterocycles, as well as the feasibility of their use for displays on exclusively organic light-emitting diodes and in complex technologies, such quantum dots color converter.
 Three thiophene structures of type T (thiophene), TB (thiophene-benzene), TPy (thiophene-pyrrole) were chosen for the study. Modeling and computing of characteristics of molecular structures was performed with the software for quantum chemical calculations Gaussian 09 due to the wide range of quantum chemical methods implemented in it, as well as high efficiency and convenient user interface.
 With the help of the selected software, modeling of molecules, optimization by B3LYP methods, and the values of HOMO and LUMO energy levels were calculated. Emission and absorption spectra of T, TB and TPy type structures were obtained. Based on the obtained results, the possible application of structures in the emitting layers of organic LEDs was determined. T-type molecules can be used as a material for creating a self-emitting layer for organic light-emitting diodes in the visible wavelength range. Molecules of the TB-type are suitable for creating devices with radiation in the ultraviolet range. Molecules of the TPy-type have no prospects for use in direct OLED radiation, but their characteristics allow us to propose these structures as sources of exciting radiation for the creation of devices with light color conversion technologies.