Related papers: Band-gap engineering at a semiconductor - crystall…
In IV-VI semiconductor heterojunctions with band-inversion, such as those made of Pb$_{1-x}$Sn$_{x}$Te or Pb$_{1-x}$Sn$_{x}$Se, interface states are properly described by a two-band model, predicting the appearance of a Dirac cone in single…
The band offsets and the chemical bonding at the interfaces between (-201) $\beta$-Ga$_2$O$_3$ and Al$_2$O$_3$ polymorphs are studied through hybrid functional calculations. For alumina, we consider four representative phases, i.e.,…
In our previous study, we have predicted the novel two-dimensional honeycomb monolayers of pnictogen. In particular, the structure and properties of the honeycomb monolayer of nitrogen, which we call nitrogene, are very unusual. In this…
Topological superconductors should be able to provide essential ingredients for quantum computing, but are very challenging to realize. Spin-orbit interaction in iron-based superconductors opens the energy gap between the $p$-states of…
Semiconductor heterostructures capable of separating photogenerated electrons and holes have a wide range of optoelectronic applications, including photodetectors, solar cells, and photocatalysts. ${\beta}$-Ga$_2$O$_3$ and rutile GeO$_2$…
Utilizing three-terminal tunnel emission of ballistic electrons and holes, we have developed a method to self-consistently measure the bandgap of semiconductors and band discontinuities at semiconductor heterojunctions without any…
We develop an approach to design, engineer, and measure band structures in a synthetic crystal composed of electric circuit elements. Starting from the nodal analysis of a circuit lattice in terms of currents and voltages, our Laplacian…
Understanding band alignment and charge transfer at complex oxide interfaces is critical to tailoring and utilizing their diverse functionality. Towards this goal, we design and experimentally validate both Ohmic- and Schottky-like charge…
In$_2$Se$_3$ is a semiconductor material that can be stabilized in different crystal structures (at least one 3D and several 2D layered structures have been reported) with diverse electrical and optical properties. This feature has plagued…
Bismuth oxyselenide (Bi$_2$O$_2$Se), a novel quasi-2D charge-carrying semiconductor, is hailed as one of the best emerging platforms for the next generation semiconductor devices. Recent efforts on developing diverse Bi$_2$O$_2$Se…
We report valence and conduction band alignments and offsets for heterojunctions between CdCr2Se4, an n-type ferromagnetic semiconductor, and the non-magnetic materials Si and GaAs, evaluated using density functional theory. We explore…
Rich functionalities of transition-metal oxides and their interfaces bear an enormous technological potential. Its realization in practical devices requires, however, a significant improvement of yet relatively low electron mobility in…
Interface structure at polar/non-polar interfaces has been shown to be a key factor in controlling emergent behavior in oxide heterostructures, including the LaFeO$_3$/$\textit{n}$-SrTiO$_3$ system. We demonstrate via high energy resolution…
Tunability of interfacial effects between two-dimensional (2D) crystals is crucial not only for understanding the intrinsic properties of each system, but also for designing electronic devices based on ultra-thin heterostructures. A…
Semiconductor heterostructure is a critical building block for modern semiconductor devices. However, forming semiconductor heterostructures of lattice-mismatch has been a great challenge for several decades. Epitaxial growth is infeasible…
We demonstrate the accuracy of the hybrid functional HSE06 for computing band offsets of semiconductor alloy heterostructures. The highlight of this study is the computation of conduction band offsets with a reliability that has eluded…
The interface between topological and normal insulators hosts metallic states that appear due to the change in band topology. While these topological states at a surface, i.e., a topological insulator-air/vacuum interface, have been studied…
The electronic band gap in conventional semiconductor materials, such as silicon, is fixed by the material's crystal structure and chemical composition. The gap defines the material's transport and optical properties and is of great…
We report first-principles density-functional pseudopotential calculations on the atomic structures, electronic properties, and band offsets of BaO/BaTiO$_3$ and SrO/SrTiO$_3$ nanosized heterojunctions grown on top of a silicon substrate.…
Epitaxial Al/GaAs/Al structures having controlled thickness of high-quality GaAs and pristine interfaces have been fabricated using a wafer-bonding technique. III-V semiconductor/Al structures are grown by molecular beam epitaxy on III-V…