High-Speed Diagnosis of Space Solar Cells and their Materials by Luminescence Imaging
Abstract
We demonstrate the effectiveness of photoluminescence (PL) and electroluminescence (EL) imaging for a high-speed diagnostic characterization of Si,InGaP2/GaAs/Ge multi-junction (MJ) and Cu(In,Ga)Se2 (CIGS) solar cells for space use. PL is also applicable to wafers without a cell structure, where the selective tuning of the excitation light is used to evaluate respective layers of multi-layered structures. The intensity of band-edge emission reflects the crystalline quality, since the intensity is proportional to the minority carrier lifetime. PL and EL imaging with a highly sensitive CCD camera are quite powerful for rapid and wide-area inspection of the uniformity of the cells as well as the distribution of defects within them. We compared the radiation effects on Si, MJ and CIGS cells, examined the durability of space-qualified MJ cells after severe thermal cycles, and investigated the nonuniformity of CIGS cells.
- Publication:
-
8th European Space Power Conference
- Pub Date:
- September 2008
- Bibcode:
- 2008ESASP.661E..96T