Colloidal quantum dots are often referred to as artificial atoms, primarily because of their atom-like electron energy spectrum. Like atoms, they can form ordered structures that are commonly referred to as quantum dot solids. In this focus we provide an overview of the electronic properties of quantum dot solids. In particular, we explore the developments that have led to the observation of high electron mobility, and the challenges and opportunities for the incorporation of quantum dot solids in optoelectronic devices.

Non-volatile memories that are faster, cheaper and less power-hungry than existing solutions might be built by using solid-state devices in which information is stored and read electrically rather than by magnetic fields. Spin-transfer-torque magnetic random access memory (STT-MRAM) — the most advanced of these emerging technologies for solid-state non-volatile memory — is about to hit the market. This Nature Nanotechnology focus overviews the prospects and remaining challenges that STT-MRAM and competing emerging technologies face in terms of mass-market commercialization.Produced with support from Spin Transfer Technologies

The field of plasmonics and metamaterials has attracted a great deal of interest over the past two decades, but despite the many fundamental breakthroughs and exciting science it has produced, it is yet to deliver on the applications that were initially targeted as most promising. This focus examines the primary fundamental hurdles in the physics of plasmons that have been hampering practical applications and highlights some of the promising areas in which the field of plasmonics and metamaterials can realistically deliver.

As a result of significant scientific and technological progress over the past ten years, the commercialization of products based on graphene and related two-dimensional materials is within reach in a range of areas, from consumer electronics to energy storage. This focus reviews the fundamental properties of graphene that are relevant to electronic and other applications, and discusses the opportunities and challenges of commercializing graphene technologies.

While power generation using silicon solar panels has steadily been increasing over the years, alternative materials that could compete with this technology in terms of efficiency and module costs are intensely being investigated. Yet, to allow for a fair assessment of new photovoltaic technologies, characterization of light-conversion performance should be conducted according to commonly agreed basic rules. This joint web focus collects a series of opinion pieces, recently published in Nature Materials,Nature NanotechnologyandNature Photonics, that discuss the importance of reporting accurate device performance.

Research in nanotechnology has grown rapidly in recent years and, like any successful field, would be expected to influence the curricula being taught at universities. However, if nanotechnology is a field defined by a length scale and not traditional subject areas, has it had a more profound effect on education? And what sort of education do future nanotechnologists need in order to thrive? Such questions and others are explored in this focus issue on nanoscience education.

Since the early 1970s, researchers have looked to use individual molecules as functional building blocks in electronic circuits, but the field of molecular electronics has been hampered by significant experimental challenges and practical devices have remained elusive. Recent improvements in the study of single-molecule junctions have, however, led to the discovery of a variety of novel effects, which could have an impact on a range of applications. This focus issue examines the challenges and opportunities for the field.

Since it was launched in October 2006, Nature Nanotechnologyhas published papers on a wide range of topics within nanoscience and technology. This web focus brings together all the papers we have published in four particularly active areas - DNA nanotechnology, graphene, nanopores and nanotoxicology - along with articles on the public perceptions of nanotechnology.

The ability of DNA to self–assemble into a variety of nanostructures and nanomachines is highlighted in a growing number of papers in Nature Nanotechnology. The appeal of DNA to nanoscientists is threefold: first, it is a natural nanoscale material; second, a large number of techniques for studying DNA are already available; and third, its ability to carry information can be exploited in the self–assembly process. DNA is also increasingly being used to organize other nanomaterials, and the related field of RNA nanotechnology is beginning to emerge.