Improvement of conversion efficiency of multicrystalline silicon solar cells by incorporating reactive ion etching texturing

• Reactive ion etching is integrated into industrial cell production line for surface texturing of mc-Si wafers.
• The acidic+RIE textured surfaces in combination with high sheet resistance emitters result in a remarkable enhancement in JSC.
• The efficiency of acidic+RIE textured cells is improved 0.51% on average compared to the acidic textured cells in mass production.
• An efficiency of 18.49% is achieved on mc-Si solar cell with conventional cell structure.

The reactive ion etching in combination with acidic etching (acidic+RIE) is applied to form the front surface texturing of 156×156 mm2 multicrystalline silicon (mc-Si) wafers in order to improve the cell efficiency. The scanning electron microscope (SEM) analyses indicate that the RIE process produces dense nanoscale ridge-like structures based on the acidic textured surfaces, and these structures generate an excellent antireflection effect. The matching processes including the post-cleaning, the phosphorus diffusion, and the deposition of silicon nitride (SiNX) antireflection coating are optimized. The acidic+RIE textured surfaces in combination with high sheet resistance emitters result in a remarkable enhancement in short wavelength response and then improve the short circuit current density (JSC) significantly. The absolute conversion efficiency of acidic+RIE textured solar cells is improved 0.51% on average compared to the acidic textured solar cells in mass production, and a maximum full-area cell efficiency of 18.49% is achieved on the mc-Si solar cell with a conventional cell structure.