A Characterization Method for Molecular Orientation of Organic Optoelectronic Materials

Abstract

The invention discloses a method for characterizing the molecular orientation of an organic photoelectric material. By establishing an optical model of the sample to be tested, the film transmission matrix of the sample to be tested is established according to the characteristic matrix of each layer of thin film in the optical model; The dielectric function model is parameterized to obtain the optical constants of the sample to be tested, the theoretical Mueller matrix spectrum of the sample to be tested is calculated according to the optical constants and the film transmission matrix, and the theoretical Mueller matrix spectrum and the measured Mueller matrix spectrum are combined by an iterative algorithm. Le matrix spectral fitting, extracting the extinction coefficient of the sample, and calculating the molecular orientation of the sample to be measured according to the relationship model between the molecular orientation and the extinction coefficient of the constructed sample to be measured; The 4×4 order Mueller matrix obtained by Mueller matrix ellipsometry is calculated and analyzed to obtain the molecular orientation of optoelectronic materials, which is suitable for fast and accurate calibration of the orientation degree of organic molecules in organic optoelectronic devices.

Description

technical field [0001] The invention belongs to the technical field of small molecule organic optoelectronics, and more specifically relates to a method for characterizing the molecular orientation of organic optoelectronic materials based on Muller matrix ellipsometer, which is applicable to the rapid determination of the molecular orientation degree of organic thin layer materials in organic optoelectronic devices. Accurate calibration. Background technique [0002] The orderly orientation of molecules is one of the most important properties of small molecule organic photoelectric material thin films; in organic light-emitting diodes, photons are emitted from the light-emitting layer, most of which are lost due to total internal reflection, changing the orientation of organic light-emitting molecules, The emission angle of the light-emitting dipole can be changed, thereby reducing the generation of the total internal reflection phenomenon, so that more photons can be effec...

AI Technical Summary

Problems solved by technology

When measuring with an ordinary ellipsometer, only two measurement parameters, the amplitude ratio and the phase difference, can be obtained under each set of measurement conditions. To characterize molecular orientation, it is necessary to measure multiple azimuth angles or multiple incident angles to obtain multiple sets of amplitude ratio and phase difference data. By changing the angle measurement method, the anisotropic film can be more sensitively characterized to determine its anisotropic optical constants. The measurement process is complex and time-consuming; in addition, the measurement process such as changing the azimuth and incident angle is usually realized by mechanical movement, which will introduce systematic errors and inevitably reduce the measurement accuracy, etc.

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