What is an EL defect detector for solar modules

　　1、 Basic principles of EL detection technology

　　What is an EL defect detector for solar modules? In short, this is a device that utilizes the principle of electroluminescence for non-destructive testing of photovoltaic modules. When a forward bias is applied to the component, the recombination of electron hole pairs in the silicon wafer releases photons. By capturing these low light signals with a high-sensitivity CCD camera, defect images with a resolution of up to μ m can be generated.

　　Compared with traditional visual inspection, the EL defect detector using solar modules can achieve:

　　The detection rate of hidden cracks has increased by 300% (from 20% to 98%)

　　Detection speed up to 15 seconds per piece (standard for conventional production lines)

　　Can identify 0.03mm microcracks and virtual solder joints

　　2、 Core components of the device

　　The EL defect detector for solar modules typically consists of three subsystems:

　　Activate power supply unit

　　Provide adjustable current from 0-20A, supporting different process components such as PERC/HJT/TOPCon. The device can still maintain an image signal-to-noise ratio of>42dB at a current density of 10mA/cm ²

　　optical imaging system

　　Adopting a scientific grade cooled CCD camera with a quantum efficiency greater than 85%. Detecting microcracks at the edges of battery cells that cannot be detected by traditional methods

　　Intelligent analysis software

　　Integrating machine learning algorithms, the images collected by the EL defect detector for solar modules can achieve:

　　Automatically classify 12 types of defects (such as black core, broken gate, etc.)

　　Linkage analysis with IV test data

　　Generate a three-dimensional thermal map of defect distribution

　　3、 Five key technological breakthroughs

　　Multispectral EL technology

　　The latest developed EL defect detector for solar modules has achieved 390-1700nm wide spectrum detection, which can synchronously obtain parameters such as carrier diffusion length

　　Dynamic bias scanning

　　By gradually changing the voltage from 0-15V, the evolution process of defects under different biases can be observed. Successfully predict the failure point of the component after 3 years using this function

　　Online detection solution

　　The EL defect detector production line version for solar modules launched in 2024 can complete 100% full inspection at a conveyor belt speed of 1.8m/s, with a misjudgment rate of less than 0.3%

　　Double sided component adaptation

　　A dual camera system developed for double-sided power generation components, capable of synchronously capturing surface defects before and after, with a 140% increase in detection efficiency

　　Quantum dot enhancement technology

　　The application of CsPbBr3 quantum dot coating increases the luminescence intensity by 8 times, making it possible for the EL defect detector of solar modules to detect perovskite modules

　　4、 Industry application value analysis

　　In terms of production quality control

　　After the module manufacturer deployed the EL defect detector for solar modules, the module's first-year attenuation rate decreased from 1.5% to 0.8%

　　Power station acceptance scenario

　　During the acceptance of the power station, it was found through the EL defect detector of the solar modules that 7.2% of the modules had installation hidden cracks, avoiding potential losses exceeding tens of millions

　　Research and development innovation field

　　Using a high-precision EL defect detector for solar modules, the microcrack occurrence rate of HJT modules was successfully reduced from 5% to 0.7%

　　Standards compliance

　　IEC TS 62941 explicitly requires that components must undergo EL testing before leaving the factory, promoting the use of EL defect detectors for solar modules as mandatory testing equipment

　　5、 Future Development Trends

　　Deep integration of AI

　　The next generation of EL defect detectors for solar modules will be equipped with AI intelligent models to achieve defect root tracing

　　Portable detection

　　Develop handheld devices weighing less than 5kg to meet the needs of power station operation and maintenance

　　multimodal fusion

　　The EL+PL+IV three in one detection system is currently undergoing trial production, and the testing efficiency will be further improved by 50%

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