Spectral Ellipsometric Fitting Method for Nanoparticles

Abstract

The invention provides a spectral ellipsometry fitting method for nanoparticles, which utilizes a spectral ellipsometer, adopts an effective medium approximation layer and a four-step fitting method, including: forming a nanoparticle material layer on a substrate to obtain the first Model, directly fit the nanoparticle material layer to obtain preliminary experimental results; form a mixed layer of nanoparticle material and air on the nanoparticle material layer, so that the obtained second model conforms to the actual nanoparticle characteristics; remove the nanoparticle material layer , change the thickness and proportion parameters of the mixed layer of nanoparticle material and air, and obtain the third model, so that the mixed layer contains nanoparticle material and air with the same proportion from the top to the bottom layer, and fit the modified mixed layer; The modified mixed layer is improved to an effective medium approximation layer for fitting, and the optical property information of the nanoparticles is obtained. This method can satisfy the mathematical fitting degree and physical morphological characteristics, and more accurately obtain the optical property information of nanoparticles.

Description

technical field [0001] The invention relates to the technical fields of optoelectronics and nano science, in particular to a spectral ellipsometric fitting method for nanoparticles. Background technique [0002] Due to the unique size effect of nanoparticles, their physical properties such as optics, electricity, heat and magnetism will change significantly compared with bulk materials. At present, they have been used in solar cells, photoelectric catalysis, optoelectronic devices, biosensors, and information storage. , imaging and biomedical fields have been widely used. [0003] The special physical properties of nanoparticles are closely related to factors such as their size, shape, and particle distance, so it is very important to accurately measure the surface morphology and optical properties of nanoparticles in experiments. The surface morphology of nanoparticles can usually be detected by scanning electron microscope SEM and atomic force microscope AFM, while the op...

AI Technical Summary

Problems solved by technology

However, when the material is discrete nanoparticles, due to the existence of air components between particles, that is, the comprehensive influence of refraction, reflection and scattering between particles-air-substrate, the optical properties of nanoparticles have deviated from the continuous For thin film materials, the direct fitting method is not only mathematically difficult to achieve perfect fitting, that is, the minimum mean square error MSE is too high, but also physically does not conform to the real situation of discrete nanoparticles, which leads to the inconsistency of the final experimental results. Credibility is greatly reduced

Images