24V 100Ah Lithium Ion Batteries

An effective texturing structure can increase short-circuit current, contributing to improved solar cell performance. This paper first detailed the corrosion behavior of silicon wafers in an HF/HNO3/H2O system. By varying the etching solution ratio, temperature, and time, the corrosion rate, silicon wafer reflectivity, and cell output parameters were investigated. The experiments found that the corrosion rate first increased and then decreased with increasing HF content in the HF/HNO3/H2O system, and increased with increasing temperature. Regarding reflectivity, the HF:HNO3 ratio of 3:1 produced the lowest reflectivity for silicon wafers. However, after PECVD anti-reflection coating, this advantage decreased slightly compared to wafers prepared under other etching conditions. Regarding cell output parameters, the HF:HNO3 ratio of 3:1 exhibited lower efficiency, while the HF:HNO3 ratio of 1:5, with a slightly higher reflectivity, achieved the highest efficiency. Based on research on the corrosion behavior of silicon wafers in an HF/HNO₃/H₂O system, this paper proposes a novel texturing method involving secondary acid etching, which differs from conventional production processes. Initially, the silicon wafer undergoes a primary etching in an HNO₃-rich etchant, followed by a secondary etching in an HF-rich etchant. This method optimizes the surface texture and reduces light reflection losses on the silicon surface. After texturing, the surface morphology of the silicon wafers was analyzed using a scanning electron microscope (SEM), and the reflectance spectrum was measured using a Carry 5000 UV-Vis-NIR spectrophotometer. The minimum reflectivity of the secondary etching process (without antireflection coating) was 20.34%, 2.36% lower than the primary etching process (22.70%). Furthermore, the new secondary etching process was applied to the industrial production of solar cells, and the cell output parameters were analyzed. Results show that the open-circuit voltage, short-circuit current, and efficiency of the solar cells treated with the secondary etching process all improved to varying degrees compared to those using the primary etching process, with the highest efficiency reaching 15.45%.