Nanowerk January 31, 2020 The bulk photovoltaic effect is a way to convert light into electrical current. An international team of researchers (USA – Boston College, UCLA, Germany, Switzerland) developed microscopic devices based on the Weyl semimetal tantalum arsenide. They had larger bulk photovoltaic effect than seen before. The devices they developed absorbed mid-infrared light, an important wavelength for devices that conduct chemical and thermal imaging as well as waste heat recovery. The observed magnitude and wavelength range of the shift current advances our fundamental understanding of the effects of topology in materials. It also demonstrates the utility of Weyl […]
Lasers etch a ‘perfect’ solar energy absorber
Nanowerk February 4, 2020 Direct femtosecond laser processing fabrication technique can effectively modify the optical, electrical, mechanical, and tribological properties of materials for a wide range of potential applications. However, it is difficult to precisely control the surface properties. Researchers at the University of Rochester have developed a process to obtain more control over spectral light absorption. They experimentally demonstrated spectral control of a variety of metals (copper aluminium, steel and tungsten), resulting in the creation of broadband light absorbers and selective solar absorbers (SSAs). They have shown that fs-laser-produced surfaces can be used as high-temperature SSAs and demonstrated that […]
New encapsulation technique protects electronic properties of sensitive materials
Science Daily January 29, 2020 Indium selenide and gallium selenide are emerging two-dimensional semiconductors with appealing electronic properties. However, they are sensitive to air and device fabrication processes which induce structural damage and hamper their intrinsic properties. An international team of researchers (USA -Columbia University, Germany, Japan) has demonstrated an encapsulating technique where two layers of hBNhexagonal boron nitride (hBN) entirely covers the 2D layers of InSe and GaSe passivating them from the environment and isolating them from the charge disorder at the SiO2 surface. They demonstrated a strong and reproducible photo response and long-term stability. The technique can open […]
New graphene amplifier unlocks hidden frequencies in the electromagnetic spectrum
Nanowerk February 3, 2020 An international team of researchers (South Korea, Russia, UK) propose a new type of optical transistor for broadband amplification of THz radiation. It is made of a graphene–superconductor hybrid, where electrons and Cooper pairs couple via Coulomb forces. The transistor operates via the propagation of surface plasmons in both layers, and the origin of amplification is the quantum capacitance of graphene. It leads to THz waves amplification, the negative power absorption, and as a result, the system yields positive gain, and the hybrid acts like an optical transistor, operating with the terahertz light. It can, in […]
New quantum switch turns metals into insulators
EurekAlert February 3, 2020 In a Mott insulator free flow of electrons is facilitated by reducing the strength of the repulsive interaction between electrons, or by changing the number of electrons. An international team of researchers (Canada, Germany, Switzerland, USA – Lawrence Berkeley National Laboratory, Ohio State University, Oak Ridge National Laboratory, South Korea) explored a way to alter the very quantum nature of the material to enable a metal-insulator transition to occur. They found that in Sr2IrO4 coupling the spin to the orbital angular momentum slows the electrons down to such an extent that they become sensitive to one […]
Scientists Warn Multiple Overlapping Crises Could Trigger ‘Global Systemic Collapse’
Science Alert February 5, 2020 Climate change, extreme weather events from hurricanes to heatwaves, the decline of life-sustaining ecosystems, food security and dwindling stores of fresh water – each poses a monumental challenge to humanity in the 21st century. Out of 30 global-scale risks, these five topped the list both in terms of likelihood and impact, according to scientists surveyed by Future Earth https://futureearth.org/ , an international research organisation. Recent research has shown that some parts of the world may soon be coping with up to six extreme weather events at once, ranging from heat waves and wildfires to diluvian […]
This simple tool can help you manage multiple research projects – How to master the art of prioritization.
Nature Index January 23, 2020 One of the most difficult things in research is to pick, prioritize, and pursue the right research projects. The life of a researcher is in many ways centered on managing and implementing a portfolio of different projects on an ongoing basis. One of the tools is the Project management triangle, which says that all projects have three constraints (scope, time, and costs), which ultimately determine the quality of the project. If you change one of these elements, it will have consequences for the other elements. Once you’ve committed to a research project, it’s also important […]
With nanogenerators, static electricity as strong as lightening can be saved in a battery
Nanowerk February 6, 2020 Researchers in South Korea have developed a one-step process of thermal nanoimprinting and simultaneous electric poling to increase the total energy obtained by each cycle of triboelectric nanogenerators (TENGs) with a ferroelectric thermoplastic polymer. They invented an integrated circuit that converted temporary and unstable electric energy generated by a triboelectric nanogenerator into reliable power source. They demonstrated that even when 2.5 µW of energy was input, the conversion efficiency recorded over 70% and that stable power of 1.8V was obtained without external power supply when this circuit was used. This amount of power was enough to […]
Top 10 Science and Technology Inventions for the Week of January 31, 2020
01. 5 Big Ideas for Making Fusion Power a Reality 02. Detection of very high frequency magnetic resonance could revolutionize electronics 03. A megalibrary of nanoparticles 04. A new twist on quantum communication in fiber 05. On the way to quantum networks 06. Smaller detection device effective for nuclear treaty verification, archaeology digs 07. Building an Orbiting Internet Just for Satellites 08. How to take a picture of a light pulse 09. Integrating microchips for electronic skin 10. What a pair! Coupled quantum dots may offer a new way to store quantum information And others… China’s Next Five-Year Energy Plan […]
5 Big Ideas for Making Fusion Power a Reality
IEEE Spectrum January 28, 2020 Over the past several years, more than two dozen research groups and well-funded startups, university programs, and corporate projects have achieved eye-opening advances in controlled nuclear fusion. Some of these groups are predicting significant fusion milestones within the next five years, including reaching the breakeven point at which the energy produced surpasses the energy used to spark the reaction. Fusion research is among the costliest of endeavors. Advances in high-speed computing, materials science, and modeling and simulation are helping to topple once-recalcitrant technical hurdles, and significant amounts of money are flowing into the field. According […]