Investigation of deep defects in nanocrystalline-Si/Si interfaces using acoustic spectroscopy

A set of structures with nanocrystalline-Si/Si interfaces formed on p-type Si substrate appropriated for photovoltaic application was prepared. The Acoustic DLTS technique based on the acoustoelectric response signal produced by the structure when a longitudinal acoustic wave propagates through the structure was used together with electric characterization to determine deep defects and the role of both individual layers. Several kinds of interface deep centers with activation energies typical for dangling bonds, oxygen participated Si or point defects were observed as well as a particular influence of individual layers on the interface states. The obtained results are analyzed, discussed and subsequently compared.