A model was developed, for H diffusion and passivation, which explained experimental observations of solar cell passivation, such as variations in the degree of passivation in differing substrates, passivation due to annealing after Al alloying, and the effects of plasma-enhanced chemical vapor deposition nitridation. Two important features of the model were a new H diffusion mechanism that involved H-vacancy complex formation, and surface damage which produced a high H solubility at the surface and the dissociation of molecular H at low temperatures. The theoretical analysis was based upon static potential energy surfaces at the  ab initio  Hartree-Fock level.

B.L.Sopori, X.Deng, J.P.Benner, A.Rohatgi, P.Sana, S.K.Estreicher, Y.K.Park, M.A.Roberson: Solar Energy Materials and Solar Cells, 1996, 41-42, 159-69