Carbon-silicon Schottky barrier diodes.

The simple fabrication of high-performance Schottky barrier diodes between silicon and conductive carbon films (C-Films) is reported. By optimizing the interface, ideality factors as low as n = 1.22 for pyrolytic photoresist films (PPF) have been obtained. These remarkable values, which are not far away from those of commercial products are obtained repeatedly on non-optimized substrates with fully scalable processes.

Using Games to Promote English as a Foreign Language Learners' Willingness to Communicate: Potential Effects and Teachers' Attitude in Focus.

This study aims to find out the role of games in promoting students' willingness to communicate (WTC) and their teachers' attitude toward it. In order to collect the data, the researchers employed a 28-item questionnaire which was given to 60 English as a Foreign Language (EFL) learners in an English institute. Then, the students were randomly divided into two groups of 30 learners functioning as control and experimental groups. The students in the experimental group received games in their language lessons and classes, while control group learners did not. At the end of the term, the same questionnaire was given to the students to know if playing games had a significant impact on their WTC. In addition, the teachers were asked to answer a 30-item questionnaire to investigate their attitudes toward playing games in language classes. The results showed that most of the teachers in this study believe that games have a positive influence on the students' attitudes towards learning English and that using them in class serves many educational purposes. In addition, games played a significant role in improving the EFL leaners' willingness to communicate. In the light of these findings, the researchers suggested using games as energizers and practical activities at the end of class not only to improve enthusiasm for learning, but also to improve the learners' WTC.

Adverse effects of nanosilver on human health and the environment.

Silver and silver nanoparticles (AgNPs) exhibit antimicrobial properties against some bacteria, fungi and viruses, however, the ever-increasing application of nanosilver in consumer products, water disinfection and healthcare settings, have raised concerns over the public health/environmental safety of this nanomaterial. The current ubiquity of nanosilver may result in repeated exposure through various routes (skin, inhalation, or ingestion) which may lead to health complications. While there are a number of review articles and case studies published to date on the subject, an updated coherent review that clearly delineates thresholds and safe doses is lacking. Thus, it is plausible to have an overview of the most recent findings on the threshold limits, safe doses of silver and its related nanoscale forms, and the needed actions to ensure the safety and health of human, terrestrial and aquatic lives. This review provides an account of the effects of nanosilver in our daily lives. STATEMENT OF SIGNIFICANCE: This manuscripts is a review of the toxicity of nanosized silver. With respect to the existing literature, it goes beyond stating that there is a knowledge gap, drawing the attention of a wider readership to the ever-growing evidence of nanosilver toxicity to human and nature, and outlining the dose thresholds based on comprehensive data mining and visualisation. There are nearly 500 consumer products that claim to contain nanosilver. Thus, we trust a review of recent conclusive findings is timely. This manuscript is in line with the scope of the Journal, enabling a better understanding of the biological response to a widely-used bionanomaterial. Moreover, it provides a bigger picture of the link between surface properties and biocompatibility of nanosilver in different forms.

Less is More: Improved Thermal Stability and Plasmonic Response in Au Films via the Use of SubNanometer Ti Adhesion Layers.

The use of a metallic adhesion layer is known to increase the thermo-mechanical stability of Au thin films against solid-state dewetting, but in turn results in damping of the plasmonic response, reducing their utility in applications such as heat-assisted magnetic recording (HAMR). In this work, 50 nm Au films with Ti adhesion layers ranging in thickness from 0 to 5 nm were fabricated, and their thermal stability, electrical resistivity, and plasmonic response were measured. Subnanometer adhesion layers are demonstrated to significantly increase the stability of the thin films against dewetting at elevated temperatures (>200 °C), compared to more commonly used adhesion layer thicknesses that are in the range of 2-5 nm. For adhesion layers thicker than 1 nm, the diffusion of excess Ti through Au grain boundaries and subsequent oxidation was determined to result in degradation of the film. This mechanism was confirmed using transmission electron microscopy and X-ray photoelectron spectroscopy on annealed 0.5 and 5 nm adhesion layer samples. The superiority of subnanometer adhesion layers was further demonstrated through measurements of the surface-plasmon polariton resonance; those with thinner adhesion layers possessed both a stronger and spectrally sharper resonance. These results have relevance beyond HAMR to all Ti/Au systems operating at elevated temperatures.

Investigation of the interfaces in Schottky diodes using equivalent circuit models.

The metal-semiconductor contact is one of the most critical factors that determine the performance of semiconductor devices such as Schottky barrier diodes (SBDs). SBDs between conductive carbon thin films and silicon have attracted attention due to their high performance and potential low cost of fabrication. Here, we introduce impedance spectroscopy (IS) as a powerful technique to characterize such SBDs. The electrical and structural characteristics of carbon-silicon SBDs between silicon and two different types of conductive carbon thin films have been investigated. Modeling the data with an extended equivalent circuit model reveals the effects of the metal electrode contacts of SBDs for the first time. From dc current-voltage measurements, diode parameters including the ideality factor, the Schottky barrier height, and the series resistance are extracted. Through use of analysis with IS, additional information on the Schottky contact is obtained, such as the built-in potential and more reliable barrier height values. Thus, IS can be utilized to analyze interfaces between metals and semiconductors in great detail by electrical means.