In the fields of manufacturing and quality control, in-situ online PL monitoring systems are becoming the core technology for improving production quality and efficiency. This advanced system based on material luminescence characteristics for non-contact detection can monitor material changes and defect generation in real-time during the production process, providing key data support for intelligent manufacturing.

　1、 Technical principles and system composition

The in-situ online PL monitoring system is based on the principle of photoluminescence: when a specific wavelength of laser is irradiated on the surface of a material, the material emits characteristic fluorescence, and its intensity, spectrum, and lifetime reflect the composition, structure, and defect state of the material. The system mainly consists of three modules: excitation light source module, spectral acquisition module, and real-time analysis module. The system achieves remote measurement through fiber optic probes and can work stably in harsh environments such as high temperature and high pressure.

　　2、 Integrated application of production line

In semiconductor manufacturing, this system is integrated into MOCVD and MBE equipment to monitor the quality of epitaxial wafer growth in real-time. By analyzing the PL spectral intensity of GaN based LED epitaxial wafers, the quality of quantum well growth can be determined online, and process parameters can be adjusted in a timely manner. In the photovoltaic industry, the system is installed on the production line of solar cells and can quickly identify defects such as microcracks, impurity distribution, and uneven resistivity by scanning PL images. The detection speed can reach over 2000 pieces per hour.

　　3、 Real time analysis and intelligent warning

The advanced PL system adopts machine learning algorithms to establish a correlation model between PL spectral features and product quality. The system can calculate key indicators such as luminous intensity uniformity, peak wavelength drift, and spectral half width in real time, and automatically trigger an alarm when the data exceeds the preset threshold. Simultaneously generate visual quality distribution maps, accurately locate defect locations, and provide intuitive basis for process optimization.

　　4、 Technological advantages and value creation

Compared to traditional offline detection, in-situ online PL monitoring has significant advantages: real-time feedback changes quality judgment from "post inspection" to "process control"; Non contact measurement to avoid sample contamination and damage; The full inspection mode replaces sampling inspection, significantly improving the level of quality control. Practical applications have shown that the use of PL monitoring in LED production lines has increased the yield of epitaxial wafers by more than 15%, and the efficiency sorting accuracy of photovoltaic cells has reached an industry-leading level of 0.1%.

　　5、 Development Trends and Challenges

With the advancement of Industry 4.0, PL systems are developing towards multi-point monitoring, high-speed imaging, and AI diagnosis. The new system integrates multiple measurement probes, which can simultaneously monitor the growth situation at different positions inside the reaction chamber; High resolution PL imaging technology can achieve micrometer level defect detection; The application of deep learning algorithms enables systems to have self optimization capabilities. The current technological challenges mainly lie in signal interference suppression in complex environments and improving the universality of multiple materials.

The in-situ online PL monitoring system, as a process perception organ in modern manufacturing, is reshaping the paradigm of quality control. By integrating scientific research level analysis technology into the industrial production environment, this system provides key technical support for achieving intelligent manufacturing and digital factories, becoming an important tool for enhancing the core competitiveness of the manufacturing industry.