Abstract: The hydrogen plasma degradation of transparent conduction oxides (TCO) is studied for hydrogenated microcrystalline Si(μc-Si:H)prepared by plasma enhanced chemical vapor deposition (PECVD).TCO films such as SnO2 and SnO2/ZnO bi-layer films were exposed to atomic H at various substrate temperatures and for various treatment times.A decrease in the transmittance due to reduction by atomic H was scarcely observed for SnO2/ZnO bi-layer,while a decrease for SnO2 was found to depend strongly on the substrate temperature.The resistivity of SnO2 films decreases significantly when substrate temperature exceeds 150℃ in H-plasma.However,H-plasma treatment has little impact on the resistivity of SnO2/ZnO bi-layer film.The reason for the decrease in the transmittance is the appearance of metallic Sn on the surface,and under this condition no μc-Si:H film is deposited.SnO2/ZnO bi-layer is very effective for the suppression of the reduction of TCO during μc-Si:H deposition.The performance of microcrystalline silicon solar cells fabricated on ZnO/SnO2/glass is also investigated.

Key words: TCO, hydrogenated microcrystalline silicon, hydrogen plasma degradation