Photovoltaics

This month, the CLEO/QELS conference has a tribute symposium to the famous laser inventor Ted Maiman. Be sure not to miss it.

The photovoltaics industry is growing fast, but it still needs to bring down costs before it can reach its true potential. Nadya Anscombe talks to Winfried Hoffmann, president of the European Photovoltaics Industry Association, to find out more.

Metamaterials have now evolved to a level where their resonant frequency can be optically tuned in the terahertz region. Nature Photonics spoke to Hou-Tong Chen from Los Alamos National Laboratory about the achievement.

Metamaterials that possess frequency tunability enable new device functions. By external optical control through the incorporation of semiconductors in metallic split-ring resonators, the researchers provide an elegant solution to frequency-agile terahertz metamaterials.

Light absorbers are not 100% efficient, and it is a challenge to absorb light completely for any direction of incidence. Using nanostructured metal surfaces, de Abajo and colleagues show that such omnidirectional absorption is now possible, potentially leading to more efficient solar cells.

The drive to develop detectors capable of counting the number of photons in a weak optical pulse is motivated by potential applications in quantum computing. Superconducting nanostructures are one exciting approach: offering high sensitivity and operate at repetition rates up to 80 MHz.

Optical-frequency antennas efficiently couple light into very small volumes. Introducing an important concept from radiofrequency antenna design, that of loading with so-called lumped circuit elements, may provide a way of tuning the frequency response of optical nanoantennas.

It has been known for many decades that tightly focusing light introduces asymmetry. The impact of this on imaging, as is now demonstrated using solid immersion lenses, is that resolution becomes dependent on the polarization of the light.

Laser-generated plasmas are important for the creation of X-ray lasers and attosecond light pulses, but observing the internal dynamics of a plasma is difficult. This paper reports a method for real-time imaging of the electric-field distribution in such plasmas with ultrahigh temporal resolution, yielding a new insight into their behaviour

Nanophotonics is in its infancy, but a recently published European roadmap is the first attempt to paint a detailed picture of the industry that could emerge in the future.

Light Up The World, a non-profit organization founded by optical engineer Dave Irvine-Halliday, is on a mission to bring safe, clean and affordable lighting to impoverished people. Nature Photonics finds out more.

The ability to tune the resonant frequency of a metamaterial in the terahertz region will help to overcome some of the limitations of customary designs demonstrated so far. The result could be a new breed of active, frequency-agile devices that are controlled by light.

The ability to distinguish how many photons comprise a particular state of light leads to significant benefits in practical quantum information processing and quantum cryptography. Superconducting nanostructures provide an effective solution at telecom wavelengths.

Optical antennas are the short-wavelength equivalent of the common radiofrequency structures. Taking this analogy one step further, the design concepts of radiofrequency lumped circuit elements can effectively be transplanted to optical wavelengths.

Researchers in Germany have shown that an ultrafast electron beam can be used to probe the dynamics of laser-generated plasmas with picosecond resolution.

By making use of polarization control, researchers have achieved a record 100-nm resolution when imaging buried transistors in an integrated circuit.

Advances at every stage of the manufacturing process are helping to reduce costs in the photovoltaics industry, but there is still a long way to go before photovoltaic cells reach their true potential.

Multijunction solar cells used in concentrator photovoltaics have enabled record-breaking efficiencies in electricity generation from the Sun's energy, and have the potential to make solar electricity cost-effective at the utility scale.

Polymer materials could bring down the cost of electricity production using photovoltaic technology to below $1 per watt for the first time, and enable mass-market, portable applications for photovoltaic technology.