A device and method for distinguishing SiNx film color of solar cell pieces

Abstract

The application relates to a SiNx film color testing device and method for distinguishing solar cell pieces. The film color testing device comprises a light source module for emitting a light beam and irradiating the surface of the cell piece at a set incident angle; a fiber spectrometer for receiving the light beam reflected by the surface of the cell piece and obtaining the reflectivity curve of the surface of the cell piece at different wavelengths; and a control module connected with the light source module and the fiber spectrometer respectively, for converting the reflectivity curve of the surface of the cell piece at different wavelengths and obtaining the color coordinates of the cell piece, and screening out cell pieces with similar colors by limiting the interval range of the color coordinates. The film color testing device can intuitively and timely understand the color of each cell piece; is used for ensuring the consistency of the overall color of the assembly, retaining data, improving product traceability and better quality control.

Description

Technical Field

[0001] This invention relates to the screening of solar cells, and more particularly to a SiNx film color testing device and method for distinguishing solar cells. Background Technology

[0002] In solar cell manufacturing, an anti-reflective coating is typically deposited on the surface to improve the photoelectric conversion efficiency of solar cells. Silicon nitride, due to its excellent optical properties, is an ideal material for this coating. However, silicon nitride films of varying thicknesses can cause dispersion of light during propagation, resulting in color differences and causing photovoltaic cells to exhibit color variations under illumination. In practical production applications, photovoltaic cells within the same module should ideally have a consistent color. Currently, even with ellipsometer measurements of film thickness to differentiate film colors, color differences still exist within the same category. Summary of the Invention

[0003] To address the above problems, this invention provides a SiNx film color testing device for distinguishing solar cells, the specific technical solution of which is as follows:

[0004] A SiNx film color testing device for distinguishing solar cells includes: a light source module for emitting a light beam and illuminating the surface of the solar cell at a set incident angle; a fiber optic spectrometer for receiving the light beam reflected from the surface of the solar cell and obtaining the reflectivity curves of the solar cell surface at different wavelengths; and a control module connected to the light source module and the fiber optic spectrometer, respectively, for converting the obtained reflectivity curves of the solar cell surface at different wavelengths to obtain the color coordinates of the solar cell, and then filtering out solar cells with similar colors by constraining the range of the color coordinates.

[0005] Preferably, the light source module includes one of an LED light source, a halogen lamp light source, or a xenon lamp light source.

[0006] Preferably, the control module includes: an industrial computer connected to the light source detection module and the light source module respectively; and a display connected to the industrial computer.

[0007] Preferably, it also includes: a dial, located on one side of the battery cell, for detecting the incident angle of the light source module.

[0008] A method for testing the color of SiNx film in solar cells, used in the aforementioned SiNx film color testing apparatus for distinguishing solar cells, includes the following steps:

[0009] Obtain the energy distribution curve and tristimulus value curve of the light source;

[0010] Obtain the reflectance curves of the solar cell surface at different wavelengths;

[0011] The energy distribution curve, tristimulus value curve, and reflectivity curve are converted to obtain the tristimulus values;

[0012] The coordinates of the corresponding white point of the light source can be found in the CIE standard illuminator table and the observer's field of view based on the obtained tristimulus values.

[0013] The color coordinates of the battery cell are obtained from the coordinates of the white point of the light source.

[0014] Constrain the range of color coordinates to filter out cells with similar colors.

[0015] Preferably, by consulting the CIE standard table, the spectral energy distribution curve S(λ) of the selected light source at different wavelengths and the tristimulus value curves x(λ), y(λ), and z(λ) of the observer are obtained.

[0016] The reflectance curves ρ(λ) of the solar cell surface at different wavelengths were obtained using a spectral detection module. The wavelength interval of the fiber optic spectrometer was 1 nm. The tristimulus values ​​X, Y, and Z were obtained through formula conversion.

[0017] X= ;

[0018] Y= ;

[0019] Z= ;

[0020] Wherein, λ1 and λ2 are the start and end wavelengths;

[0021] The coordinates Xn, Yn, and Zn of the white point of the light source can be found in the CIE standard illuminant table and the observer's field of view. Substituting these coordinates into the color coordinate formula:

[0022] ;

[0023] ;

[0024] ;

[0025] Where L, a, b are the color coordinates of the solar cell;

[0026] Constrain the range of values ​​L, a, and b to filter out cells with similar colors.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention provides a SiNx film color testing device for distinguishing solar cells. It obtains reflectivity curves after irradiating the cell, converts these curves at different wavelengths to obtain the cell's color coordinates, and then filters cells with similar colors by constraining the range of these color coordinates. The device is simple in structure and easy to use, applicable not only to silicon nitride thin film color sorting but also to other thin film color sorting. It provides a direct and real-time understanding of the color of each cell, ensuring the overall color consistency of the module while retaining data, improving product traceability, and enabling better quality control. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0030] The present invention will now be further described with reference to the accompanying drawings.

[0031] like Figure 1 As shown, a SiNx film color testing device for distinguishing solar cells includes a light source module, a fiber optic spectrometer, and a control module. The light source module emits a light beam and illuminates the surface of the solar cell at a set incident angle. The fiber optic spectrometer receives the light beam reflected from the surface of the solar cell and obtains the reflectivity curves of the solar cell surface at different wavelengths. The control module is connected to both the light source module and the fiber optic spectrometer. It converts the obtained reflectivity curves of the solar cell surface at different wavelengths to obtain the color coordinates of the solar cell, and then filters out solar cells with similar colors by constraining the range of the color coordinates.

[0032] The light source module includes one of the following: LED light source, halogen lamp light source, or xenon lamp light source.

[0033] The control module includes an industrial computer and a display. The industrial computer is connected to the light source detection module and the light source module, respectively; the display is connected to the industrial computer.

[0034] It also includes: a dial, located on one side of the battery cell, used to detect the incident angle of the light source module.

[0035] A light beam is incident on the solar cell at a specific angle, and then the reflection spectrum is received at a fixed angle.

[0036] This device is suitable not only for silicon nitride thin film color sorting, but also for other thin film color sorting.

[0037] Depending on the test object, the light source can be LED, halogen lamp, xenon lamp, etc.

[0038] It can be divided into two modes: offline and online. In offline mode, the color of the solar cell film can be manually distinguished. This mode is mostly used for experimental comparison studies. In online mode, it is integrated with automation. It uses TCP / IP or IO communication to connect the testing device with automation. During the test, the color value parameters are automatically classified and graded according to the constraint range.

[0039] Different incident and receiving angles can be selected for testing according to customer needs.

[0040] By introducing colorimetric principles, the X, Y, and Z tristimulus values ​​are obtained by multiplying the spectral power distribution curve of the light source by the spectral reflectance curve of the object by a standard observer. Then, based on the different light sources and the observer's field of view, appropriate data are selected to calculate L (luminance), a (color channel), and b (color channel). Different L, a, and b values ​​correspond to different colors. Color sorting and inspection of the cell film significantly improves the appearance of photovoltaic modules, providing a direct and real-time understanding of the color of each cell. This ensures the overall color consistency of the module while retaining data, enhancing product traceability, and enabling better quality control.

[0041] A method for testing the color of SiNx films in solar cells includes the following steps:

[0042] Obtain the energy distribution curve and tristimulus value curve of the light source;

[0043] Obtain the reflectance curves of the solar cell surface at different wavelengths;

[0044] The energy distribution curve, tristimulus value curve, and reflectivity curve are converted to obtain the tristimulus values;

[0045] The coordinates of the corresponding white point of the light source can be found in the CIE standard illuminator table and the observer's field of view based on the obtained tristimulus values.

[0046] The color coordinates of the battery cell are obtained from the coordinates of the white point of the light source.

[0047] Constrain the range of color coordinates to filter out cells with similar colors.

[0048] The specific steps are as follows:

[0049] According to the CIE standard table, the spectral energy distribution curve S(λ) of the selected light source at different wavelengths and the tristimulus value curves x(λ), y(λ), and z(λ) of the observer are obtained.

[0050] The reflectance curves ρ(λ) of the solar cell surface at different wavelengths were obtained using a spectral detection module. The wavelength interval of the fiber optic spectrometer was 1 nm. The tristimulus values ​​X, Y, and Z were obtained through formula conversion.

[0051] X= ;

[0052] Y= ;

[0053] Z= ;

[0054] Wherein, λ1 and λ2 are the start and end wavelengths;

[0055] The coordinates Xn, Yn, and Zn of the white point of the light source can be found using the CIE standard illuminant table and the observer's field of view. Substituting these parameters into the color coordinate formula:

[0056] ;

[0057] ;

[0058] ;

[0059] Where L, a, b are the color coordinates of the solar cell;

[0060] Constrain the range of values ​​L, a, and b to filter out cells with similar colors.

[0061] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the claims of the present invention.

Claims

1. A SiNx film color testing device for distinguishing solar cells, characterized in that, include: The light source module is used to emit a light beam and illuminate the surface of the battery cell at a set incident angle; A fiber optic spectrometer is used to receive light beams reflected from the surface of solar cells and obtain the reflectivity curves of the solar cell surface at different wavelengths. as well as The control module is connected to the light source module and the fiber optic spectrometer respectively. It is used to convert the reflectance curve of the solar cell surface at different wavelengths to obtain the color coordinates of the solar cell. Then, by constraining the range of the color coordinates, solar cells with similar colors are screened out to ensure that the overall color of the component remains consistent. In obtaining the color coordinates, the energy distribution curve, tristimulus value curve, and reflectance curve are converted to obtain the tristimulus values. Based on the obtained tristimulus values, the corresponding white point coordinates of the light source can be found in the CIE standard illuminant table and the observer's field of view. The color coordinates of the solar cell are obtained based on the white point coordinates of the light source.

2. The SiNx film color testing device for distinguishing solar cells according to claim 1, characterized in that, The light source module includes one of LED light source, halogen lamp light source or xenon lamp light source.

3. The SiNx film color testing device for distinguishing solar cells according to claim 1, characterized in that, The control module includes: An industrial control computer is connected to both the fiber optic spectrometer and the light source module; and The monitor is connected to the industrial control computer.

4. The SiNx film color testing device for distinguishing solar cells according to claim 1, characterized in that, Also includes: The dial, located on one side of the battery cell, is used to detect the incident angle of the light source module.

5. A method for testing the color of SiNx film in distinguishing solar cells, used in the SiNx film color testing apparatus for distinguishing solar cells as described in claim 1, characterized in that, Includes the following steps: Obtain the energy distribution curve and tristimulus value curve of the light source; Obtain the reflectance curves of the solar cell surface at different wavelengths; The energy distribution curve, tristimulus value curve, and reflectivity curve are converted to obtain the tristimulus values; The coordinates of the corresponding white point of the light source can be found in the CIE standard illuminator table and the observer's field of view based on the obtained tristimulus values. The color coordinates of the battery cell are obtained from the coordinates of the white point of the light source. Constrain the range of color coordinates to filter out cells with similar colors.

6. The method for testing the color of SiNx film in solar cells according to claim 5, characterized in that, According to the CIE standard table, the spectral energy distribution curve S(λ) of the selected light source at different wavelengths and the tristimulus value curves x(λ), y(λ), and z(λ) of the observer are obtained. The reflectance curves ρ(λ) of the solar cell surface at different wavelengths were obtained using a spectral detection module. The wavelength interval of the fiber optic spectrometer was 1 nm. The tristimulus values ​​X, Y, and Z were obtained through formula conversion. ； ； ； Where λ1 and λ2 are the start and end wavelengths; the corresponding white point coordinates Xn, Yn, and Zn of the light source can be found in the CIE standard illuminant table and the observer's field of view. Substituting the white point coordinates of the light source into the color coordinate formula: ； ； ； Where L, a, b are the color coordinates of the solar cells; by constraining the range of the three values ​​of L, a, b, solar cells with similar colors are selected.

Images