PROCESS-DEVELOPMENT OF AMORPHOUS-SILICON CRYSTALLINE SILICON SOLAR-CELLS

We have already investigated some crucial limiting process steps of th e amorphous silicon (a-Si)/crystalline silicon (c-Si) solar cell techn ology and some specific characterization tools of the ultrathin amorph ous material used in devices. In this work, we focus our attention par ticularly on the technology of the ITO front contact fabrication, that also is used as an antireflective coating. II is pointed out that thi s layer acts as a barrier layer against the diffusion of metal during the annealing treatments of the front contact grid. The criteria of th e selection of the metal to be used to obtain good performance of the grid and the deposition methods best suited to the purpose are shown. We were able to fabricate low temperature heterojunction solar cells b ased p-type Czochralski silicon, and a conversion efficiency of 14.7% on 3.8 cm(2) area was obtained without back surface field and texturiz ation.