Processes for over 18.5% high-efficiency multi-crystalline silicon solar cell

This paper reports the improvement of a high-efficiency mass-production process for large area multi-crystalline silicon (mc-Si) solar cells. A new cell structure and optimization of fabrication process has achieved 18.6% efficiency with mc-Si wafer in practical size of 15 cm × 15 cm, independently confirmed by National Institute of Advanced Industrial Science and Technology (AIST). Main fabrication process of the development are as follows; (1) novel texturization method by combination of laser patterning and wet chemical etching, (2) optimization for screen printing metallization process of firing profile condition, front and back metal electrode material, (3) reduction shading losses of front grid electrode by using modified screen and front metal electrode.