We report the observation of an order of magnitude enhancement of the thermoelectric figure of merit (ZT = 0.36) in topological insulator Bi1.5Sb0.5Te1.7Se1.3 nanowires at 300 K as compared with the bulk specimen (ZT = 0.028). The enhancement was primarily due to an order of magnitude increase in the electrical conductivity of the surface-dominated transport and thermally activated charge carri...

We have performed low-temperature measurements on a gated two-dimensional electron system in which electron-electron (e-e) interactions are insignificant. At low magnetic fields, disorder-driven movement of the crossing of longitudinal and Hall resistivities (ρxx and ρxy) can be observed. Interestingly, by applying different gate voltages, we demonstrate that such a crossing at ρxx ~ ρxy can oc...

The extracellular ionic microenvironment has a close relationship to biological activities such as by cellular respiration, cancer development, and immune response. A system composed of ion-sensitive field-effect transistors (ISFET), cells, and program-controlled fluidics has enabled the acquisition of real-time information about the integrity of the cell membrane via pH measurement. Here we ai...

A magnetic domain boundary on the surface of a three-dimensional topological insulator is predicted to host a chiral edge state, but direct demonstration is challenging. We used a scanning superconducting quantum interference device to show that current in a magnetized topological insulator heterostructure (EuS/Bi2Se3) flows at the edge when the Fermi level is gate-tuned to the surface band gap...

This study investigates the effect of gate insulators on thin-film transistors (TFTs) using an amorphous InGaZnO4 (a-IGZO) channel layer. TFTs with single-layer Ta2O5 and dual-layer Ta2O5/SiO2 were fabricated a glass substrate. An evaluation insulating film MIM (Metal-Insulator-Metal) structure confirmed its electrical characteristics. Microscopic imaging showed that dielectric significantly im...

one of the important factors influencing outdoor insulators performance is pollution phenomenon. the pollution, especially during humidity condition, reduces superficial resistance of insulator and lead to a flow of leakage currents (lc) on the insulator surface, which may result in total flashover. the lc characteristics are affected by parameters such as nature and severity of pollution. loca...

An inkjet-printed silver electrode and a spin-coated cross-linked poly(4-vinylphenol)(PVP) dielectric layer were used as a gate electrode and a gate insulator for a bottom-gate pentacene thinlm transistor (TFT), respectively. The printing and the curing conditions of the printed silver electrode were optimized and tested on various substrates, such as glass, silicon, silicon dioxide, polyethers...

To minimize leakage currents resulting from the thinning of the insulator in the gate stack of field effect transistors, high-dielectric constant high-k metal oxides, and HfO2 in particular, are being implemented as a replacement for SiO2. To speed the rate of processing, it is desirable to etch the gate stack e.g., metal gate, antireflection layers, and dielectric in a single process while hav...

Recently, the magnetic topological insulator (TI) MnBi2Te4 emerged as a competitive platform to realize quantum anomalous Hall (QAH) states. We report Berry curvature splitting mechanism QAH effect in disordered TI multilayers when switching from an antiferromagnetic order ferromagnetic order. reveal that of spin-resolved curvature, originating separation critical points during switching, can g...

Time-periodic perturbation can be used to modify the transport properties of the surface states of topological insulators, specifically their chiral tunneling property. Using the scattering matrix method, we study the tunneling transmission of the surface states of a topological insulator under the influence of a time-dependent potential and finite gate bias voltage. It is found that perfect tr...