Realization of single terminated surface of perovskite oxide single crystals and their band profile: (LaAlO3)0.3(Sr2AlTaO6)0.7, SrTiO3 and KTaO3 case study

To characterize the physical properties of thin films without ambiguity and design interface with new functionalities, it is essential to have detailed knowledge of physical properties and appropriate estimation of the band profile of perovskite oxide substrates. We have developed and demonstrated a chemical free unified framework to realize single terminated surface of KTaO3, (LaAlO3)0.3 (Sr2AlTaO6)0.7 and SrTiO3 (001) oriented single crystals. The electronic band line-up of these single crystal substrates, using a combination of optical spectroscopy and Kelvin Probe Force Microscopy, has been constructed. A polar-polar interface of KTaO3 and LaBO3 (B-Transition metal ion) before and after the possible surface/electronic reconstruction has also been schematically presented.