In the production process of photovoltaic cells, the cleaning and texturing process is a crucial step, and its main purpose is to improve the photoelectric conversion efficiency of the cells. This process involves two key steps: cleaning and texturing, each of which has a profound impact on the performance of the final product. 3D Confocal Microscope performs well in this process and can accurately measure the microstructure of the silicon wafer after texturing, such as key parameters such as the height, uniformity and roughness of the texturing surface. The equipment's high-precision measurement function helps manufacturers optimize the texturing process and reduce production defects, thereby improving production efficiency and photoelectric conversion efficiency. Thanks to its excellent performance and reliability, 3D Confocal Microscope has won wide acclaim and has become the inspection equipment of choice for many photovoltaic companies.

Basic principles of cleaning and texturing process

First of all, the cleaning step is the basis of the entire production process. Before texturing, the silicon wafer must be thoroughly cleaned to remove all contaminants from its surface, including dust, grease, and other particles. If these contaminants are not removed, they will seriously affect the effectiveness of subsequent texturing steps and may even lead to an overall decrease in cell efficiency.

Effect of metal impurities on cell performance

The cleaning process usually involves the following steps:

•Pre-cleaning: Use deionized water or a slight surfactant solution to remove most coarse contaminants on the surface of the silicon wafer by spraying or soaking.

•Chemical cleaning: Use acid and alkali solutions for deeper cleaning. Commonly used chemicals such as hydrofluoric acid and nitric acid mixed solutions can effectively remove the oxide layer and organic pollutants on the surface of silicon wafers.

•Ultrasonic cleaning: After chemical cleaning, ultrasonic technology is used to further disperse and remove tiny particle contaminants in a water bath, ensuring the highest standards of cleanliness on the silicon wafer surface.

These methods can effectively remove the pollution layer and oxide layer on the surface of the silicon wafer, creating a clean and uniform surface for the next texturing process.

Textured effect on polycrystalline silicon surface under electron microscope

The next texturing process enhances the performance of photovoltaic cells by forming tiny textured structures on the surface of the silicon wafer. This structure is actually tiny irregularities that can increase the reflection and refraction of light within the silicon wafer, thereby extending the journey of light inside the silicon crystal. This effect, known as "light trapping," allows more light to be absorbed by the silicon wafer and converted into electricity. The textured surface structure is formed in the following ways:

•Wet etching: Use chemical etching to form a micron-scale pyramid-shaped structure on the surface of the silicon wafer. These structures can increase the reflection and refraction of light within the silicon wafer, forming light trapping and effectively extending the journey of light within the silicon crystal.

•Dry etching: Using plasma technology, a more uniform and regular textured structure can be formed on the surface of the silicon wafer to further optimize light absorption and conversion efficiency.

ideal textured surface picture

The effective textured structure can significantly reduce the reflectivity of surface light, allowing light energy to be absorbed by the silicon wafer more effectively, ultimately improving the photoelectric conversion efficiency.

By precisely controlling cleaning and texturing conditions, such as chemical concentration, processing time, temperature, etc., the formation of these surface structures can be optimized to ensure that the surface of the silicon wafer achieves the best optoelectronic performance. Therefore, cleaning and texturing are not only basic steps in the manufacturing process, but also a key link in optimizing photovoltaic cell performance.

Application of 3D Confocal Microscope in Quality Control

3D Confocal Microscope ME-PT3000, plays an integral role in the manufacturing process of photovoltaic cells, especially in the quality inspection stage after the cleaning and texturing steps. Using cutting-edge optical technology, we accurately measure steep slopes and complex surface structures on photovoltaic cells, providing detailed height and width distribution data in real time. In this way, the microstructural details created during the texturing process - such as the number and dimensions of the pyramidal textures - were analyzed in detail to ensure they effectively increase light reflection and refraction within the silicon wafer, thereby lengthening the light path. , increase the generation of photogenerated carriers and improve photoelectric conversion efficiency.

3D Confocal Microscope

E-mail: market@millennialsolar.com

•Accurate and reliable 3D measurement to achieve real-time confocal microscopy images

•Ultra-high confocal lens, Z-axis display resolution up to 1nm

•198-39966 times maximum comprehensive magnification, accurate measurement of sub-micron level morphology

•Fully automatic grating textured surface measurement, quickly generate data

•Comprehensive feedback on cleaning texturing and screen printing processes

3D Confocal Microscope ME-PT3000 is not only a powerful tool for detecting and validating processes, but also a key device for optimizing the production process and improving the quality of the final product. We are always committed to providing strong technical support to manufacturers and making continuous contributions to the development of the photovoltaic industry. We hope that every photovoltaic cell will reach the highest performance standards