Test method for refractive index of solar cell antireflection film

Abstract

The invention discloses a test method for the refractive index of a solar cell antireflection film. The method comprises the steps of: (1) employing a reflectivity tester to measure the refractive index of the solar cell antireflection film to obtain a reflectivity curve, taking the wavelength corresponding to a lowest point on the reflectivity curve, and representing the wavelength by lambda 0; (2) using a scanning electron microscope to detect the thickness of the antireflection film where the refractive index of the solar cell antireflection film is measured, taking an average value, and representing it by d; (3) applying the numerical values into the formula n=lambda 0 / (4*d), thus obtaining the refractive index of the antireflection film. The invention develops a new test method for the refractive index of the solar cell antireflection film. Experiments prove that, the test method provided by the invention can carry out accurate measurement on the antireflection film growing on any texturing structure surface, and the measuring result is accurate and reliable.

Description

technical field [0001] The invention relates to a method for testing the refractive index of an anti-reflection film of a solar cell, belonging to the technical field of solar energy. Background technique [0002] Currently, solar cells are the dominant product in the photovoltaic market. In the manufacturing history of solar cells, in order to improve the conversion efficiency of solar cells, the technology of depositing anti-reflection films on the surface of silicon wafers has become one of the main means. Commonly used anti-reflection coatings include silicon nitride, silicon oxide, silicon carbide, titanium oxide, and tantalum oxide; the existing technology uses one of these films or the superposition of several films; this can greatly reduce the incidence of incident light. Reflection, thereby improving the utilization of light by solar cells. [0003] In the prior art, in order to control and evaluate the quality of the anti-reflection film, two parameters, film thi...

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Problems solved by technology

However, the existing ellipsometer test has the following problems: (1) The ellipsometer is sensitive to the surface structure of the anti-reflection coating, and the value measured on the polished sheet is usually more accurate, followed by the value measured on the micron suede surface, and the nanometer The value measured on the suede surface is generally inaccurate; (2) the physical model in the existing ellipsometer is limited, and the calculation error of the system between different models is relatively large; the ellipsometer commonly used in laboratories and production in the industry There are only two models of silicon nitride and silicon oxide. With the development of thin film technology, the types and structures of thin film materials are becoming more and more diverse. The existing ellipsometer obviously cannot perform accurate measurements.

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