Despites huge research funding for photovoltaics, contribution of solar cells to energy market is still negligible. The major obstacle is high production cost of silicon solar cells: current solar cell market is dominated by silicon technology. Bulky and rigid silicon solar cell with a power conversion efficiency above 10% and a lifetime of 25 years have become the benchmark in photovoltaic industry. However, there are plenty of scopes for disposable and inexpensive solar cells with a moderate efficiency and a shorter lifetime, which can be compared with plant leaves with a typical efficiency of 3-7% and a lifetime less than a year. Here is an example of research that was motivated to produce cheap and disposable solar cells with a moderate power conversion efficiency.
Today we are going to tackle a general topic that deals with how data is represented in scientific papers. The use of illustrations in scientifi c publications is a longstanding tradition that goes back thousands of years. In the course of writing 1,200 Nanowerk Spotlights over the past six years, we have worked our way through thousands of papers. And if one thing has stood out, it is the quality of the illustrations included in these papers: some are just excellent and capture the essence of the findings; others, well, let's just say they could be improved upon. Here are five specific recommendations on how scientists should design effective figures.
Every aspect of cellular activities, including cell proliferation, differentiation, metabolism and apoptosis, can be regulated by a class of tiny but very important nucleic acids fragments called microRNAs (miRNAs). They bind to specific messenger RNAs and cause messenger RNA degradation or inhibit translation, thereby regulate gene expression at the post-translational level. In cancer cells, the homeostasis of these normal biological processes is disrupted, partially by dysregulated miRNAs, therefore the level of microRNAs is an indicator to the disease development, and miRNAs in cancer tissues or biofluids can be utilized as a diagnostic biomarker for cancer detection. Now, researchers report a miRNAs-based discovery that could provide a much earlier warning signal for lung cancer.
Along with graphene, atomically thin sheets and ribbons of boron nitride (often called "white graphene") have increasingly attracted fundamental research interest. While researchers make good progress on developing techniques for mass-producing graphene, it is still a challenge to reliably chemically delaminate and/or exfoliate boron nitride and to realize mass production of atomically thin sheets made of this material. Researchers in Japan have now reported a new approach for synthesizing boron nitride monolayers which pretty much works like blowing a balloon; although these balloons are sized in a range of tens of micrometers. The new technique solves the problem of low-throughput fabrication of 2D crystals.
Memristors - the fourth fundamental two-terminal circuit element following the resistor, the capacitor, and the inductor - have attracted intensive attention owing to their potential applications for instance in nanoelectronic memories, computer logic, or neuromorphic computer architectures. Scientists have been able to show that various materials such as metal oxides, chalcogenides, amorphous silicon, carbon, and polymer-nanoparticle composite materials exhibit memristive phenomena. One unanswered question so far has been whether natural biomaterials like proteins can be used for the fabrication of solid-state devices with transport junctions. Researchers in Singapore have now demonstrated that proteins indeed can be used to fabricate bipolar memristive nanodevices.
Bio-conjugated nanoparticles are important analytical tools with emerging biological and medical applications. Especially gold nanoparticles are of increasing interest for nanobiotechnology research and applications because of their high acceptance level in living systems and the fact that they are fairly easily conjugated with functional molecules. Ultrashort pulsed laser ablation represents a powerful tool for the generation of pure gold nanoparticles avoiding chemical precursors, reducing agents, and stabilizing ligands. The bare surface of the charged nanoparticles makes them highly available for functionalization and as a result especially interesting for biomedical applications. Starting today, such conjugates are available commercially for the first time.
Harvesting unexploited energy in the living environment to power small electronic devices and systems is increasingly attracting the attention of research groups around the world. As device sizes shrink to the micro- and even nanoscale, power consumption also decreases to ever lower levels, i.e. microwatts to milliwatts range. And as research findings have shown over the past few years, it is entirely possible to drive such minuscule devices by directly scavenging energy from their working environment. A recent example is the integration of nanogenerators into the inner surface of tires, demonstrating the possibility of energy harvesting from the motion of automobiles.
Dye-sensitized solar cells (DSSCs) are among the most promising photovoltaic devices for low-cost light-to-energy conversion with relatively high efficiency. While the DSSC is a fairly mature design, researchers are still trying to improve its efficiency with various techniques. To date, the most commonly used counter electrode in DSSC is fluorine doped tin oxide glass coated with a thin layer of platinum. However, as a noble metal, the low abundance and high cost hinder platinum from being used for large-scale manufacturing. In the quest to seek alternative counter electrode materials for expensive and scarce platinum, a group of scientists has now explored the use of abundant ternary or quaternary materials as potential substitutes for platinum.