Kompetenzzentrum für Mikro- und Nanotechnologien

In this work, we demonstrated a process for the large area passivating and contacting of nanowire based solar cells. The nanowire based solar cells were prepared on layered laser crystallization (LLC)polycrystalline silicon (pc-Si)thin films with thickness less than 2 μm. It was demonstrated that the space between the nanowires can be filled with a passivating dielectrics Al2O3layer, and the nanowire tips can be exposed by a self-regulating selective etching of the Al2O3deposited on the tips and that on the sidewalls. The exposed tips of the nanowires can be connected by a transparent conducting aluminium doped zinc oxide (Al:ZnO or AZO)layer deposited by atomic layer deposition (ALD). It is demonstrated by laser beam induced current mapping (LBIC)that the current density can increase up to 63% at 633 nm due to light trapping and the superior passivation of the nanowires with an thin pc-Si film of only 1.73 μm.