In this Letter, we report gate-tunable X-ray photoelectron emission from back-gated graphene transistors. The back-gated transistor geometry allows us to study photoemission from graphene layer and the dielectric substrate at various gate voltages. Application of gate voltage electrostatically dopes graphene and shifts the binding energy of photoelectrons in various ways depending on the origin...

When pushing the gate dielectric thickness of metal-oxide-semiconductor (MOS) devices down to the subnanometer scale, the most challenging issue is the interface. The interfacial transition layers between the high-k dielectric/Si and between the high-k dielectric/gate metal become the critical constraints for the smallest achievable film thickness. This work presents a detailed study on the int...

In this thesis we study the interactions of ions and cationic peptides with a negatively charged lipid bilayer in an ionic solution where the electrostatic interactions are screened. We first examine the problem of charge renormalization and inversion of a highly charged bilayer with low dielectric constant. To be specific, we consider an asymmetrically charged lipid bilayer, in which only one ...

A micrometer-sized electroacoustic DNA-biosensor was developed. The device included a thin semi-crystalline polyethylene terephthalate (PET) dielectric layer with two Ag microband electrodes on one side and a DNA thiol-labeled monolayer adsorbed on a gold surface on the other. A resonance wave was observed at 29 MHz with a network analyzer, upon AC voltage application between the two Ag electro...

This study unveils a new tetracene derivative that forms dense, upright monolayers on the surface of aluminum oxide. These monolayers spontaneously self-organize into the active layer in nanoscale field-effect transistor devices when aluminum oxide is used as the dielectric layer. This method gives high yields of working devices that have source-drain distances that are less than 60 nm, thereby...

Active modulation of ions and molecules via field-effect gating in nanofluidic channels is a crucial technology for various promising applications such as DNA sequencing, drug delivery, desalination, and energy conversion. Developing a rapid and facile fabrication method for ionic field-effect transistors (FET) over a large area may offer exciting opportunities for both fundamental research and...

We combine conductive atomic force microscopy (CAFM) and molecular dynamics (MD) simulations to reveal the interaction of atomically thin layered materials (ATLMs) down to nanoscale lateral dimension. The setup also allows quantifying, for the first time, the effect of layer number and electric field on the dielectric constant of ATLMs with few-layer down to monolayer thickness. Our CAFM-assist...

Thin dielectric layers deposited on the inner surface of hollow cylindrical metallic waveguides for Terahertz (THz) waves reduce transmission losses below 1 dB/m. Impact of the dielectric layer on the waveguide dispersion is experimentally investigated by near-field mapping of guided short THz pulses at the input and the output of the waveguide. We obtain dispersion characteristics for the low-...

Electrowetting on dielectric (EWOD) is a promising technology for variable focus liquid microlens. When an electrical field is applied across a liquid droplet and a dielectric layer, the contact angle of the liquid can be tuned with different applied voltages. Therefore, the focal length of a microlens would vary by simply applying an electrical field without any moving mechanical components. I...

a theory is presented for the dispersion relations of the nonlinear phonon-polaritons arising when phonons are coupled to the electromagnetic waves in multilayered structures of nonlinear materials. the calculations are applied to a multilayered structure consisting of a thin film surrounded by semi-infinite bounding media where each layer may have a frequency dependent dielectric function and ...