Challenges in Low-Cost Chalcogenide Solar Cells toward Tens of GW EraChallenges in Low-Cost Chalcogenide Solar Cells toward Tens of GW Era Challenges in Low-Cost Chalcogenide Solar Cells toward Tens of GW Era
A conversion efficiency of 22.3% on Cu(In,Ga)(Se,S)2 (CIS-based) cell has been achieved. This is the highest efficiency in not only all thin-film PV but also multi crystalline Si PV. The efficiency improvement encourages expansion of production volume. In the future, tens of GW era on the CIS-based PV could be realized. In the case, the material cost is considered to be one of the biggest factors in the cost structure. In order to reduce the material cost, we are focusing on In-free and Se-free chalcogenide solar cells as next generation solar cells. For the In-free cells, the efficiency of Cu2ZnSn(Se,S)4 cell and submodule have been reached 12.7% and 11.8%, respectively. For the Se-free cells, the efficiency of pure-sulfide Cu(In,Ga)S2 cell and submodule have been reached 15.5% and 13.2%, respectively. In this presentation, we would review our recent progresses on our In-free and Se-free approaches.