ZnS deposition onto bare and GaSe terminated Silicon-(111)-surfaces

The electronic properties and growth morphology of Si(111)/ZnS heterostructure modified by a GaSe van der Waals termination layer, which provides a chemical and an electronic passivation of the Si(111)-surface is investigated by surface sensitive methods (STM, LEED and SXPS). The van der Waals termination layer suppresses the Si-S interface reaction, which is observed for non terminated substrates. The interface electronic properties are nearly unchanged, but the morphology of the growing ZnS-film is dramatically changed. With the passivation layer ZnS grows as orientated pyramides with a (111) base area surface orientaion and (100)-facets. The sticking coefficient is reduced by a factor of 10 compared to bare Si(111), where ZnS grows as an untextured polycrystalline layer.