| 摘要 |
A CIS solar cell having flexibility and high conversion efficiency may be produced, using, as a substrate, a polyimide film which is prepared from an aromatic tetracarboxylic acid component comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride as the main component and an aromatic diamine component comprising p-phenylenediamine as the main component, and has a maximum dimensional change in the temperature-increasing step of from 25 °C to 500 °C within a range of from +0.6 % to +0.9 %, excluding +0.6 %, based on the dimension at 25 °C before heat treatment. |
