Related papers: Pb-doped p-type Bi$_2$Se$_3$ thin films via interf…
The \emph{p}-type Bi$_{2}$Se$_{3}$ is much desirable as a promising thermoelectric material and topological insulator, while the naturally grown Bi$_{2}$Se$_{3}$ is always \emph{n}-type doped by native point defects. Here we use…
Spatially controlling the Fermi level of topological insulators and keeping its electronic states stable are indispensable processes to put this material into practical use for semiconductor spintronics devices. So far, however, such a…
The unique surface edge states make topological insulators a primary focus among different applications. In this article, we synthesized a large single crystal of Niobium(Nb)-doped Bi2Se3 topological insulator (TI) with a formula…
Topological insulators (TIs) are novel materials that manifest spin-polarized Dirac states on their surfaces or at interfaces made with conventional matter. We have measured the electron kinetics of bulk doped TI Bi$_2$Se$_3$ with angle…
A simple surface band structure and a large bulk band gap have allowed Bi2Se3 to become a reference material for the newly discovered three-dimensional topological insulators, which exhibit topologically-protected conducting surface states…
Topological insulators are materials with an insulating bulk interior while maintaining gapless boundary states against back scattering. Bi$_2$Se$_3$ is a prototypical topological insulator with a Dirac-cone surface state around $\Gamma$.…
The first experimental evidence is presented of the topological insulator state in PbBi$_{2}$Te$_{4}$. A single surface Dirac cone is observed by angle-resolved photoemission spectroscopy (ARPES) with synchrotron radiation. Topological…
Topological insulators are a new class of insulators with conducting surface state. Most of the topological insulators are chalcogenides, where a tiny amount of chalcogen vacancy destroys the predicted bulk insulating state and results in a…
High quality thin films of topological insulators (TI) such as Bi2Se3 have been successfully synthesized by molecular beam epitaxy (MBE). Although the surface of MBE films can be protected by capping with inert materials such as amorphous…
Although $\beta$-TeO$_2$ is a promising $p$-type transparent conducting oxide (TCO) due to the large optical gap ($\sim$ 3.7 eV) and a light effective hole mass, its hole dopability still remains unexplored. In this work, electronic…
Two essential ingredients for the quantum anomalous Hall (QAH) effect, i.e. topological and magnetic orders, can be combined by doping magnetic ions into a topological insulator (TI) film. Through this approach, the QAH effect has been…
Introducing an isolated intermediate band (IB) into a wide band gap semiconductor can potentially improve the optical absorption of the material beyond the Shockley-Queisser limitation for solar cells. Here, we present a systematic study of…
A new doping mechanism is described, whereby a doping impurity does not simply transfer charge to the bands of a host semiconductor or semimetal, but rearranges the core energy levels deep in the valence band of the host. This, in turn,…
Magnetic devices are a leading contender for implementing memory and logic technologies that are nonvolatile, that can scale to high density and high speed, and that do not suffer wear-out. However, widespread applications of magnetic…
Layered narrow band gap semiconductor Bi2Se3 is composed of heavy elements with strong spin-orbital coupling (SOC), which has been identified both as a good candidate of thermoelectric material of high thermoelectric figure-of-merit (ZT)…
We present resistivity and magnetization measurements on proton-irradiated crystals demonstrating that the superconducting state in the doped topological superconductor Nb$_x$Bi$_2$Se$_3$ (x = 0.25) is surprisingly robust against…
Topological superconductivity is an exotic quantum phenomenon with coupled nontrivial topological order and superconductivity together. A direct idea for producing topological superconductors is to create superconductivity based on the well…
Bi2Se3 is theoretically predicted1 2and experimentally observed2,3 to be a three dimensional topological insulator. For possible applications, it is important to understand the electronic structure of the planar device. In this work,…
In the recently discovered class of materials known as topological insulators, the presence of strong spin-orbit coupling causes certain topological invariants in the bulk to differ from their values in vacuum. The sudden change of…
We consider in our work high quality single crystal thin films of Bi2Se3, grown by molecular beam epitaxy, both with and without Pb doping. Our ARPES data demonstrate topological surface states with a Fermi level lying inside the bulk band…