Evolution of fully European triple GaAs solar cells
The first generation of fully European triple junction solar cells is of 27% class (RWE3G-27%class) with an area of 8cm×4cm minus two cropped corners and an ID2 integral by-pass diode concept in which the adjacent cell is protected. An additional by-pass diode concept for extreme temperature applications is available by using a new structure of external Si diode. It is planned to use this triple junction GaAs cell (RWE3G-27%class) for several European satellite projects such as Aeolus, Pleiades, Herschel (one section) and Proba 2. The paper reports the production experience and the output with this 27% class triple cell in the framework of these projects. The second generation is of 28% class (RWE3G-28%class), with the same configuration and area. This cell has an improved EOL performance of R(Pmax) (E15-1MeV electrons/cm2) 0.85. Details on qualification testing and first production experience for this cell type will be presented. Finally the current development results for the third generation - 29% to 30% class cell - with further improved EOL performance of R(Pmax) = 0.88 and monolithic by-pass diode will be reported together with a road map of further potential development using cell structures made from III-V material system.