Abstract
Front and rear surface passivation layers on n-type Si were analyzed that can be implemented in a high efficiency back-contact back-junction solar cell. The front surface features a phosphorus diffused layer which is passivated with a thin thermal oxide and an antireflection silicon nitride layer. In order to assess the quality of the oxide of the newly developed oxidation processes of the Photovoltaic Technology Evaluation Center (PV-TEC), they were compared to the thin oxide films fabricated at the clean room. For the rear side, different passivation layers and stacks were compared to each other. In addition to the firing stability, the spiking behavior of aluminum paste was investigated. The lowest surface saturation current densities after firing and annealing reached were J0s,front = 61 fA/cm2 on a textured surface for the front side and J0s,rear = 17 fA/cm2 on a plane surface for the rear side, which results in Voc limit,front = 681 mV and Voc,limit,rear = 714 mV respectively.