Interfacial phenomena in nanocapacitors with multifunctional oxides

First principles simulations of Pt/PbZrTiO3 interfaces demonstrate how interfacial interactions defines the effectiveness of the screening, and ease of polarisation switching in nanocapacitors with multifunctional oxide.

Recent Progress in Atomic Layer Deposition of Multifunctional Oxides and Two-Dimensional Transition Metal Dichalcogenides

Atomic layer deposition (ALD) has long been developed for conformal coating thin films on planar surfaces and complex structured substrates based on its unique sequential process and self-limiting surface chemistry. In general, the coated thin films can be dielectrics, semiconductors, conductors, metals, etc., while the targeted surface can vary from those of particles, wires, to deep pores, through holes, and so on. The ALD coating technique, itself, was developed from gas-phase chemical vapor deposition, but now it has been extended even to liquid phase coating/growth. Because the thickness of ALD growth is controlled in atomic level ([Formula: see text]0.1[Formula: see text]nm), it has recently been employed for producing two-dimensional (2D) materials, typically semiconducting nanosheets of transition metal dichalcogenides (TMDCs). In this paper, we briefly introduce recent progress in ALD of multifunctional oxides and 2D TMDCs with the focus being placed on suitable ALD precursors and their ALD processes (for both binary compounds and ternary alloys), highlighting the remaining challenges and promising potentials.

Electrically Coupling Multifunctional Oxides to Semiconductors: A Route to Novel Material Functionalities

ABSTRACTComplex oxides and semiconductors exhibit distinct yet complementary properties owing to their respective ionic and covalent natures. By electrically coupling oxides to semiconductors within epitaxial heterostructures, enhanced or novel functionalities beyond those of the constituent materials can potentially be realized. Key to electrically coupling oxides to semiconductors is controlling the physical and electronic structure of semiconductor – crystalline oxide heterostructures. Here we discuss how composition of the oxide can be manipulated to control physical and electronic structure in Ba1-xSrxTiO3/ Ge and SrZrxTi1-xO3/Ge heterostructures. In the case of the former we discuss how strain can be engineered through composition to enable the re-orientable ferroelectric polarization to be coupled to carriers in the semiconductor. In the case of the latter we discuss how composition can be exploited to control the band offset at the semiconductor - oxide interface. The ability to control the band offset, i.e. band-gap engineering, provides a pathway to electrically couple crystalline oxides to semiconductors to realize a host of functionalities.

Probing and Analyzing Buried Interfaces of Multifunctional Oxides Using a Secondary Electron Energy Analyzer

A contactless method of probing and analyzing multifunctional oxide interfaces using an electron energy analyzer inside a scanning electron microscope is presented. High contrast experimental secondary electron analyzer signals are used to detect changes in the interface conductivity of a LaAlO3/SrTiO3 sample. Monte Carlo simulations of the primary beam/specimen interaction are carried out and correlated with the experimental results in order to help understand the role of the primary beam energy and adjust it to enhance contrast.