CdTe solar cell glass substrate and solar cell using the same

摘要

CdTe solar cell glass with a high balance of high transmittance, high glass transition temperature, predetermined average thermal expansion coefficient, high glass strength, low glass density, solubility during plate glass production, formability, and devitrification prevention A substrate and a solar cell using the same are provided. The present invention, in a molar percentage based on the following oxides, the SiO ₂ 60 to 75% of _{Al 2 O 3 1~7.5%, B} 2 O 3 0 to 1 percent, MgO 8.5 to 12.5%, CaO 1-6.5%, SrO 0-3%, BaO 0-3%, ZrO ₂ 0-3%, Na ₂ O 1-8%, K ₂ O 2 -12%, MgO + CaO + SrO + BaO 10-24%, Na ₂ O + K ₂ O 5-15%, MgO / Al ₂ O ₃ is 1.3 or more, (2Na ₂ O + K ₂ O + SrO + BaO) / (Al ₂ O) ₃ + ZrO ₂ ) is 3.3 or less, Na ₂ O / K ₂ O is 0.2 to 2.0, Al ₂ O ₃ ≧ −0.94MgO + 11, CaO ≧ −0.48, MgO + 6 0.5, and the glass transition temperature is 640 ° C. or higher and the average heat at 50 to 350 ° C. Zhang coefficient ^{70 × 10 -7 ~90 × 10 -7} / ℃, viscosity temperature to be ^{_{10 4 dPa · s (T 4}} ) is 1230 ° C. or less, the temperature at which the viscosity becomes ^{_{10 2 dPa · s (T 2}} ) Relates to a glass substrate for a CdTe solar cell in which the relationship between T ₄ and the devitrification temperature (T _L ) is T ₄ −T _L ≧ −30 ° C. and the density is 2.7 g / cm ³ or less.