| 摘要 |
A glass substrate for a CIGS solar cell containing specific amounts of SiO2, Al2O3, B2O3, MgO, CaO, SrO, BaO, ZrO2, TiO2, Na2O and K2O, respectively. The glass substrate satisfies the specific requirements regarding MgO+CaO+SrO+BaO, Na2O+K2O, MgO/Al2O3, (2Na2O+K2O+SrO+BaO)/(Al2O3+ZrO2), Na2O/K2O, the relation of Al2O3 and MgO, and the relation of CaO and MgO, respectively. The glass substrate has a glass transition temperature of 640° C. or higher, an average coefficient of thermal expansion within a range of 50 to 350° C. of 70×10-7 to 90×10-7/° C., the temperature (T4) of 1,230° C. or lower, the temperature (T2) of 1,650° C. or lower, and a density of 2.7 g/cm3 or less. The glass substrate satisfies the relationship of T4-TL>=-30° C. |
