Hardened Violet Response Silicon Solar Cell for Satellite Application.

This contract involved development of further hardened versions of violet response solar cells, by adding aluminum contacts, and by testing the effects of higher resistivity silicon. The conventional violet cells improved steadily in output during the contract 70-79 mw 2x2 Cm There were difficulties in applying suitable fine line aluminum contacts to the shallow diffused front surface of the cell. The best violet cells with aluminum contacts were about 10 lower in output than the usual violet cells. Radiation tests showed that low resistivity 1-3 ohm-cm silicon still gave best overall cell performance. Limited environmental tests showed that the performance of violet cells was satisfactory. More intensive study of the overall contact properties is suggested. Violet cells with both conventional and aluminum contacts, and covering a decade of bulk resistivity values, were delivered for evaluation, and for associated tests.