Interaction between bulk and surface passivation mechanisms in thin film solar cells on defected silicon substrates

Common features of thin film silicon (TFSi-) solar cells hydrogenated in a microwave induced remote plasma (MIRP) are studied. The thin films were epitaxially grown on ribbons and multicrystalline silicon (mc-Si). Optimal hydrogenation renditions are presented in relation to the sample conditions such as the surface passivation, the active carrier concentration in the epitaxial layer and the substrate material. The MIRP-hydrogenation is studied in the temperature range of 350-415°C. A high passivation efficiency is observed at 400°C for all substrates in spite of an unfavourable hydrogenation regime at 375°C. In the absence of an oxide during the hydrogenation, an optimal hydrogenation time of 1 hour is observed irrespective of the substrate used. This optimal hydrogenation time is a consequence of the interaction between the incoming atomic hydrogen and the boron dopant in the epitaxial layer