| Sažetak: | Passivated contact cell architectures have the potential for higher efficiencies than
the currently dominant PERC technology. Further development requires greater understanding
of the passivation mechanism and potential surface related degradation, especially at
polysilicon-oxide-crystalline silicon contacts. In particular, the hydrogenation provided by
high temperature firing of dielectrics has been shown to govern both initial passivation and
subsequent degradation at this interface. Given the nanoscale dimensions of the tunnelling
oxide, assessing the concentration of hydrogen at the interface is a complex task. In this work
we use atom probe tomography to demonstrate the capacity to resolve hydrogen atoms at this
interface. Atom probe tomography can provide improved depth resolution via 3D
reconstructions of the elemental atomic distributions at the interface. We propose a route
towards atomic scale measurements of hydrogen across a thin tunnelling oxide, which can
enable further understanding of charge carrier flow at or near this interface. We show that the
ability to characterise hydrogen at the nanoscale is crucially limited by the residual gas present
during the atom probe measurement. Therefore deuterium, as a surrogate for naturally abundant
hydrogen, is recommended to accurately provide less ambiguous determination of hydrogen
concentrations at the atom scale in such structures. However, even with the use of deuterium
challenges remain, and the analysis and interpretation of the data must be undertaken with care.
Such atom scale characterisation can provide critical information on the role that hydrogen
plays in passivating contact interfaces.
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