Properties of mixed phase silicon-oxide-based passivating contacts for silicon solar cells

Temperature-dependent IV-measurements at solar cell level were performed in order to understand the physical mechanisms behind charge carrier transport and surface passivation of the mixed-phase SiOx/Si layer stack. The results were compared to those of a standard silicon heterojunction (SHJ) cell on a similar planar substrate. The temperature dependence of the IV-curves in the range from -100°C to +75°C reveals that the hybrid cell is less temperature sensitive with respect to the SHJ cell. Furthermore, at low temperatures, the analysis reveals a reduction of the VOC temperature coefficient of the hybrid cell, whereas for the SHJ cell a saturation occurs. This behaviour hints that the barrier imposed by the SiOx/Si-based contact is less pronounced than the barrier imposed by a standard SHJ contact.