Ever since the first cadmium selenide quantum dot-based light-emitting devices (QLEDs) were reported in 1994, the dominant materials for QLEDs investigated since then have been limited to wurtzite or zinc blende Cd-based QDs. Similarly, the best developed and studied colloidal QD lasers have been fabricated from Cd-based semiconductors. Now, researchers have presented a new family of photoelectric materials for light-emitting devices: colloidal all-inorganic perovskite cesium lead halide QDs. This new material could find applications in LEDs and lasers, and has an especially big potential in high-performance displays, lighting, monochromatic narrow-band photodetectors, and optical communications.
Compared to the conventional inefficient incandescent and fluorescent lighting technologies, LED light bulbs can, in principle, operate at an efficiency level of 100%. The current LED lighting technology, however, is not even close to reaching this limit. This is due to several problems which, however, can be by and large solved by employing tunnel junction integration into current nanowire LED structures. Demonstrating this, researchers have developed tunnel junction nanowire LEDs that can eliminate the use of resistive p-GaN contact layers, leading to reduced voltage loss and enhanced hole injection.
The complexity of the microenvironment of a biological cell is influenced by many factors, including surface topography and chemistry; matrix stiffness; mechanical stress; molecular liquid composition and other physiochemical parameters. However, most artificial biointerfaces are developed based on just a single chemical or physical factor to direct cell behaviors. The functions performed by these artificial biointerfaces are far simpler than those performed in the natural cell microenvironment. In an effort to more closely mimic a cell's natural environment, researchers have fabricated an antibody modified reduced graphene oxide platform and used it to significantly improve the efficiency for capturing circulating tumor cells.
Given the huge economic incentives, corrosion prevention and protection is a major business. The advanced materials that are being developed and used in modern industries require increasingly sophisticated coatings for improved performance and durability. Take for example the case of microbially induced corrosion (MIC) - one of the lesser understood forms of corrosion where micro-organisms manifest metallic surfaces and induce substantial damage that often goes unnoticed until there is a loss in the component functionality. New research features graphene as a promising novel surface coating that can be used to minimize metallic corrosion under harsh microbial conditions.
The age of wearable electronics is upon us as witnessed by the fast growing array of smart watches, fitness bands and other advanced, next-generation health monitoring devices such as electronic stick-on tattoos. In order for these wearable sensor devices to become fully integrated into sophisticated monitoring systems, they require wireless interfaces to external communication devices such as smartphones. This requires far-field communication systems that, like the sensor systems, perform even under extreme deformations and during extended periods of normal daily activities.
Setting up or upgrading a lab to conduct state-of-the-art DNA nanotechnology is not an inexpensive undertaking. The hardware alone can easily set you back several hundreds of thousands of dollars. Analogous to the open-source software approach, increasingly instruments and specialized equipment designs are also developed as part of a growing open source scientific hardware (OSSH) movement. Adding to the list, a recent article presents three examples of open source/DIY technology with significantly reduced costs relative to commercial equipment.
A carbon material with high electrical conductivity, high specific surface area, tunable pore structure, mechanically robust framework, and high chemical stability is an important requirement for advanced electrochemical energy storage. However, neither porous carbon or sp2 carbon can full meet these requirements yet. How to create a conductive carbon material with especially large pore volume, and hence large surface area, has therefore been a key focus in electrode research.
Researchers have demonstrated that perfect orbital angular momentum could be generated in optical nanostructures inspired by catenaries - the curve that a free-hanging chain assumes under its own weight. They used optical catenary-shaped structures to convert circularly polarized light to helically-phased beam carrying orbital angular momentum. Similar to the 'catenary of equal strength', the phase gradient of the optical catenary is equal everywhere, which is a direct result of its special geometric shape.