Glass substrate for Cu-In-Ga-Se solar cell and solar cell using same

摘要

A glass substrate for a CIGS solar cell, having high cell efficiency and high glass transition temperature is provided. The glass substrate for a vapor-deposited CIGS film solar cell has a glass transition temperature of at least 580° C. and an average thermal expansion coefficient of from 70×10⁻⁷ to 100×10⁻⁷/° C., wherein the ratio of the average total amount of Ca, Sr and Ba within from 10 to 40 nm in depth from the surface of the glass substrate to the total amount of Ca, Sr and Ba at 5,000 nm in depth from the surface of the glass substrate is at most 0.35, and the ratio of the average Na amount within from 10 to 40 nm in depth from the surface of the glass substrate after heat treatment to such average Na amount before the heat treatment is at least 1.5.