ИСТИНА

In this work we have investigated different surface passivation schemes, which utilize indium-tin oxide (ITO) layers as an antireflection coating and a transparent electrode at the same time. ITO/Si/ITO and ITO/a-Si:H/Si/a-Si:H/ITO structures, deposited by spray pyrolysis and magnetron sputtering were investigated. For TCO/a-Si:H stacks the a-Si:H buffer layer was deposited using a plasma enhanced chemical vapour deposition (PECVD) set up. Magnetron sputtering of ITO layers was done at temperatures below 200 ºC and deposition of such layers by spray pyrolysis was done at temperatures around 400 ºC. Surface morphology of ITO layers was analyzed by the atomic force microscopy (AFM) method. The surface passivation properties were investigated by means of the effective recombination lifetime as measured by the quasi-steady-state photoconductance (QssPC) technique. It is shown that for both investigated technologies of the ITO deposition the best passivation properties has an ITO/a-Si:H stack. It is concluded that an implementaion of the ITO/a-Si:H stack for the solar cell processing require development of a low temperature metallization scheme.