Search for: All records

In recent years, lanthanum aluminate/strontium titanate (LAO/STO) heterointerfaces have been used to create a growing family of nanoelectronic devices based on nanoscale control of LAO/STO metal-to-insulator transition. The properties of these devices are wide-ranging, but they are restricted by nature of the underlying thick STO substrate. Here, single-crystal freestanding membranes based on LAO/STO heterostructures were fabricated, which can be directly integrated with other materials via van der Waals stacking. The key properties of LAO/STO are preserved when LAO/STO membranes are formed. Conductive atomic force microscope lithography is shown to successfully create reversible patterns of nanoscale conducting regions, which survive to millikelvin temperatures. The ability to form reconfigurable conducting nanostructures on LAO/STO membranes opens opportunities to integrate a variety of nanoelectronics with silicon-based architectures and flexible, magnetic, or superconducting materials. 

The prospect of 2‐dimensional electron gases (2DEGs) possessing high mobility at room temperature in wide‐bandgap perovskite stannates is enticing for oxide electronics, particularly to realize transparent and high‐electron mobility transistors. Nonetheless only a small number of studies to date report 2DEGs in BaSnO₃‐based heterostructures. Here, 2DEG formation at the LaScO₃/BaSnO₃(LSO/BSO) interface with a room‐temperature mobility of 60 cm² V⁻¹ s⁻¹at a carrier concentration of 1.7 × 10¹³ cm^–2is reported. This is an order of magnitude higher mobility at room temperature than achieved in SrTiO₃‐based 2DEGs. This is achieved by combining a thick BSO buffer layer with an ex situ high‐temperature treatment, which not only reduces the dislocation density but also produces a SnO₂‐terminated atomically flat surface, followed by the growth of an overlying BSO/LSO interface. Using weak beam dark‐field transmission electron microscopy imaging and in‐line electron holography technique, a reduction of the threading dislocation density is revealed, and direct evidence for the spatial confinement of a 2DEG at the BSO/LSO interface is provided. This work opens a new pathway to explore the exciting physics of stannate‐based 2DEGs at application‐relevant temperatures for oxide nanoelectronics.