Ag-alloying enables wide-bandgap (1.69 eV) chalcopyrite solar cell with 11.5% efficiency and over 900 mV open circuit voltage from molecular solution

Development of wide-bandgap solar cells is important to expand the application scenarios of photovoltaic. Pure sulfide chalcopyrite Cu(In,Ga)S2 (CIGS) with high stability are ideal absorber materials for these applications. The CIGS are mostly fabricated from vacuum-method with low-bandgap (VOC) of 904 mV with a bandgap of 1.69 eV, the highest efficiency and lowest VOC loss of wide-bandgap CIGS solar cell.