PROGRESS IN AMORPHOUS AND "MICROMORPH " SILICON SOLAR CELLS

ABSTRACT: LP-CVD ZnO has been developed at IMT as front TCO for amorphous silicon p-i-n single-junction and “micromorph ” (microcrystalline/amorphous silicon) tandem solar cells. In comparison with SnO2 (Asahi type U), ZnO demonstrates superior light-trapping behaviour. Applying the monolithic series connection by laser-scribing, both for amorphous single-junction and micromorph tandem cells, modules have been fabricated on LP-CVD ZnO. After light-soaking, mini-modules, with an aperture efficiency of 8.5 % in the case of amorphous silicon cells, and of 9.8 % (initial 11%) in the case of micromorph cells, could be obtained. Micromorph tandem cells with an intermediate TCO reflector between the amorphous top and the microcrystalline bottom cell reveal an almost stable performance with respect to light-soaking. A first corresponding module with the applied intermediate TCO reflector could be fabricated