Quality monitoring system for solar silicon single crystal rod

Abstract

The invention relates to the technical field of photovoltaic power generation, in particular to a solar silicon single crystal rod quality monitoring system which can monitor minority carrier lifetime and resistivity of a currently produced crystal rod in real time. When abnormality is detected, the system can automatically feed back to the corresponding control coil base to give an alarm, and determines whether to stop crystal pulling and freeze an abnormal crystal bar according to the state of the coil base. Meanwhile, the system can also judge whether the abnormity is caused by the current section output by comparing the minority carrier lifetime of the current section and the minority carrier lifetime of the upper section crystal bar, trace abnormal raw materials and batches, and calculate the abnormal attenuation proportion. If the abnormal attenuation proportion reaches or exceeds a preset threshold value, the system freezes the raw materials and pushes the raw materials for analysis. According to the invention, the real-time monitoring of the quality of the solar silicon single crystal rod is realized through an automatic means, the production efficiency and the product quality are improved, the labor cost is reduced, and the accuracy of anomaly analysis is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and particularly to a quality monitoring system for solar silicon single crystal rods. Background Art

[0002] Solar power generation plays a significant role in promoting energy transformation, protecting the ecological environment, and mitigating climate change. As the basic material for photovoltaic power generation, crystalline silicon accounts for 70% of the cost in solar cells; the minority carrier lifetime is one of the key indicators for measuring the quality of solar cell materials, which is directly related to the short-circuit current and open-circuit voltage of solar cells, and thus affects the overall performance of the cells.

[0003] Monocrystalline silicon solar cells usually use P-type silicon material with a crystal plane of <100> as the base material, and form an N-type semiconductor by diffusing pentavalent phosphorus atoms, thereby forming a PN junction to achieve photoelectric conversion. Currently, the raw materials for preparing single crystal rods include virgin polysilicon and recycled materials; during the single crystal pulling process, due to the purity of the raw materials and the introduction of metals during the process, the minority carrier lifetime of the single crystal rod will be affected. During the pulling process, after the abnormal attenuation of the minority carrier lifetime (for example, the minority carrier lifetime drops from 500 μs to 50 μs, and the normal standard is 100 μs), the cause of the abnormality will be quickly investigated. At this time, a large amount of manpower is required, and it is considered that during the investigation process, personal subjective opinions and errors will inevitably exist, resulting in inaccurate investigation results and unable to effectively monitor the quality of the crystal rod. Summary of the Invention

[0004] The present invention provides a quality monitoring system for solar silicon single crystal rods, which effectively solves the quality problems in single crystal silicon production, improves the overall automation level, and significantly reduces the labor cost and production risk.

[0005] In order to achieve the object of the present invention, the technical solution adopted is: a quality monitoring system for solar silicon single crystal rods, including a detection module and a judgment module;

[0006] 1) The detection module detects the minority carrier lifetime and resistivity of the currently produced crystal rod. If there is no abnormality, the crystal pulling is not intervened; if there is an abnormality, it is fed back to the corresponding control furnace platform and an alarm is given; if this furnace platform has completed refeeding, the current crystal rod directly enters the completion stage; if this furnace platform is in the process of refeeding, the refeeding is stopped, the pulling is stopped, and the abnormally produced crystal rods in this section are frozen.

[0007] 2) The judgment module compares the minority carrier lifetime of the crystal rods produced in this section with that of the crystal rods produced in the previous section to judge whether the abnormality is produced in this section. If it is determined that the abnormality is produced in this section, the raw materials and batches used in this section are traced, and the abnormal attenuation ratio of all furnace platforms after putting in this raw material is calculated. If the abnormality is not produced in this section, the system traces all the crystal rods produced by the furnace platform to find the abnormal sections and traces them as above.

[0008] As an optimized solution of the present invention, if the abnormal attenuation ratio ≥ 5%, the raw materials are frozen and pushed for analysis; the abnormal attenuation ratio = the number of times of abnormal attenuation of raw materials / the total number of times of raw material feeding.

[0009] As an optimized solution of the present invention, in 1), the situations where there are abnormalities include that the resistivity range is 0.5 - 0.7 Ω·cm and the minority carrier lifetime range < 200 μs.

[0010] As an optimized solution of the present invention, in 2), if the minority carrier lifetime of the upper section - the minority carrier lifetime of this section ≥ 200 μs, it is the abnormal attenuation of the output of this section.

[0011] The present invention has positive effects: 1) The present invention automatically identifies the abnormality of the quality of the ingot and takes solving measures, and at the same time automatically traces the abnormal raw materials and freezes the relevant materials. Advantages ①: Reduce labor; ② Through system control, it is more accurate and reliable, and there is no missed report or false report; ③ Automatically trace the relevant raw materials and analyze them, and the analysis accuracy is higher, improving the overall automation level.

[0012] 2) The present invention realizes the real-time monitoring of the quality of solar silicon single crystal ingots through automated means, greatly improving the production efficiency and product quality. The system can accurately identify and process abnormal situations, avoiding subjective opinions and errors in the manual inspection process, and improving the accuracy and reliability of the monitoring results. Through the automatic traceability function of the system, the cause of the abnormality can be more accurately located, providing strong support for subsequent abnormal analysis and processing, and at the same time reducing production losses caused by unknown abnormal reasons. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0014] Figure 1 is the flow chart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] To make the objectives, technical solutions and advantages of the embodiments of this patent clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

[0016] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way limits the present invention, its application or uses. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0017] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention.

[0018] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships. For technologies, methods, and devices known to those skilled in the art, they may not be discussed in detail. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other example numerical values of the exemplary embodiments may have different values.

[0019] As Figure 1 shown, the present invention discloses a quality monitoring system for solar silicon single crystal rods, including a detection module and a judgment module;

[0020] 1) Detect the minority carrier lifetime and resistivity of the currently produced crystal rod and make a judgment: A. If there is no abnormality, do not interfere with the crystal pulling and continue to monitor the quality of the next crystal rod produced; B. If there is an abnormality, feedback the abnormality information to the corresponding control furnace platform and give an alarm; if this furnace platform has completed recharging, directly enter the end section of the current crystal rod and stop pulling; if this furnace platform is in the process of recharging, stop recharging and stop pulling, and freeze the abnormally produced crystal rods in this section;

[0021] 2) Compare the minority carrier lifetime of the crystal rod produced in this section with that of the crystal rod produced in the previous section to determine whether it is an abnormality in the current section. If it is determined to be an abnormality in the current section, trace the raw materials and batches used in this section, calculate the abnormal attenuation ratio of the output after all furnace platforms input this raw material. If the abnormal attenuation ratio ≥ 5%, freeze the raw materials and push them for analysis; the abnormal attenuation ratio = the number of abnormal attenuation times of the raw material / the total number of times the raw material is input. If it is not an abnormality in the current section, the system traces all the crystal rods produced by the furnace platform, finds the abnormal sections, and traces them as described above.

[0022] In 1), the situations of abnormalities are as shown in Table 1 below: Both the required resistivity range and the minority carrier lifetime range need to be satisfied.

[0023] Table 1 Minority Carrier Lifetime Range Table

[0024] Resistivity range (Ω·cm) Minority carrier lifetime range (μs) 0.4-0.5 ＜100 0.5-0.7 ＜200 0.7-0.9 ＜250 0.9-1.1 ＜300

[0025] In 2), if the minority carrier lifetime in the previous section - the minority carrier lifetime in this section ≥ 200 μs, it is an abnormal attenuation in the current section.

[0026] The quality monitoring system for solar silicon single crystal rods of the present invention is an automatic control system, which solves the problems of consuming a large amount of manpower to investigate and freeze relevant materials after related anomalies occur, and at the same time has a higher accuracy in analysis, including the following points:

[0027] 1. Automatically identify crystal rod anomalies: For the furnace platforms with abnormal attenuation of minority carrier lifetime, timely detect and give early warnings, reduce the output of low-efficiency crystal rods, and freeze the produced low-efficiency crystal rods to prevent them from flowing out;

[0028] 2. Trace the raw materials used for low-efficiency crystal rods: Trace the manufacturers, batches, etc. of the raw materials used for low-efficiency crystal rods, combine the output data of other furnace platforms put into use with this raw material and batch, calculate the abnormal attenuation ratio after the use of this raw material, and push it to relevant personnel for auxiliary analysis;

[0029] 3. Reduce labor costs: The system automatically identifies, gives early warnings, and calculates, reducing the amount of data statistically by personnel; reducing the working hours of personnel;

[0030] 4. Improve accuracy: Through system control calculation, the calculation results are more accurate, without false negatives or false positives.

[0031] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A solar silicon single crystal rod quality monitoring system, characterized by: It includes a detection module and a judgment module; 1) The detection module detects the minority carrier lifetime and resistivity of the currently produced crystal rod. If there is no abnormality, it does not intervene in the crystal pulling; if there is an abnormality, it is fed back to the corresponding control furnace and an alarm is issued; if this furnace has completed the re-investment, the root crystal rod directly enters the completion stage; if this furnace is re-investing, it stops the re-investment and stops pulling, and freezes the abnormal crystal rod produced in this stage; 2) The judgment module compares the minority carrier lifetime of the crystal rod produced in this section with the minority carrier lifetime of the crystal rod produced in the previous section to determine whether it is an abnormality in the current section. If it is determined to be an abnormality in the current section, the raw materials and batches used in this section are traced back, and the abnormal attenuation ratio of the output after all furnaces are put into this raw material is calculated. If it is not an abnormality in the current section, the system traces back all the crystal rods produced by the furnace, finds the abnormal section number, and traces back as described above.

2. A solar silicon single crystal rod quality monitoring system according to claim 1, characterized in that: If the abnormal attenuation ratio is ≥5%, the raw materials will be frozen and pushed for analysis; abnormal attenuation ratio = number of abnormal attenuation times of raw materials / total number of times raw materials are used.

3. A solar silicon single crystal rod quality monitoring system according to claim 2, characterized in that: In 1), the abnormal conditions include a resistivity range of 0.5-0.7 Ω·cm and a minority carrier lifetime range of <200 μs.

4. A solar silicon single crystal rod quality monitoring system according to claim 3, characterized in that: In 2), if the minority carrier lifetime of the previous segment minus the minority carrier lifetime of the current segment ≥ 200μs, it is an abnormal attenuation of the output of the current segment.

Images