We demonstrate liquid-metal-mediated homoepitaxial crystal growth of Ge on Ge( 111) at temperatures in the range of 400-450 “C. Crystal growth proceeds by diffusion of Ge through a liquid layer, followed by precipitation onto the substrate by the vapor-liquid-solid mechanism. The liquid-metal phase at the interface is a Au-Ge alloy formed by initial deposition of a thin Au layer above the eutec...

The effects of orientation on flow boiling critical heat flux (CHF) were investigated using high-speed video and microphotographic techniques. Interfacial features were measured just prior to CHF and statistically analyzed. A dominant wavy vapor layer regime was observed for all relatively high-velocities and most orientations, while several other regimes were encountered at low velocities, in ...

Recent studies have established that atmospheric water vapor fields exhibit spatial spectra that take the form of power laws and hence can be compactly characterized by scaling exponents. The power law scaling exponents have been shown to exhibit substantial vertical variability. In this work, Taylor’s frozen turbulence hypothesis is used to infer the first-order spatial structure function and ...

Intercalation doping has been theoretically and experimentally studied on chemical vapor deposition synthesized few-layer graphene. Density functional theory calculations identified FeCl3 as a good dopant to reduce the sheet resistance of few-layer graphene. A simple vapor transfer method is employed to dope graphene. The successful doping is confirmed by the Raman spectra as well as the electr...

Film bulk acoustic resonators (FBARs) are widely applied in mass bio-sensing and pressure sensors, owing to their extreme sensitivity and integration ability, and ability to miniaturize circuits. A volatile organic compound (VOC) sensor with a polymer-coated diaphragm, using FBARs as a strain sensing element is proposed and optimized. This vapor sensor is based on organic vapor-induced changes ...

This study presents a chemical vapor sensor based on polymer-coated microsphere resonators. A theoretical simulation of the sensor response is performed, and optimization of the polymer layer thickness is investigated. Results show that the sensor exhibits a good linearity and a low detection limit of the refractive index change. Especially at the thermostable thickness of the polymer layer, th...

We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction...

105 points 106 points Application: Polynuclear growth Random model for layer by layer growth [1] 1. Initially a flat crystal in contact with supersaturated vapor. 2. At a random later time, a supercritical nucleus forms, and spreads laterally via attachment of particles at the perimeter. 3. New layers are randomly nucleated upon existing layers. 4. When islands within the same layer collide, th...

A highly-efficient inverted heterojunction perovskite solar cell was prepared. A homogeneous and compact perovskite (CH3NH3PbI3) layer was prepared via a two-step solution deposition method, and subsequently a double-layer PCBM film was deposited by a sequential spin-coating/vapor deposition process as the electron transport layer. The optimised device could achieve a 12.2% (average 11.09%) eff...

The primary removal of product water in proton exchange membrane (PEM) fuel cells is through the cathode gas diffusion layer (GDL) which necessitates the understanding of vapor and liquid transport of water through porous media. In this investigation, the effect of microporous layer (MPL) coatings, GDL thickness, and polytetrafluorethylene (PTFE) loading on the effective water vapor diffusion c...