Volume 6 Issue 3, March 2012

Plasmons are free-electron oscillations in a conductor that allow light to be manipulated at the nanoscale. The ability of plasmons to guide and confine light on subwavelength scales is opening up new design possibilities for solar cells.

Solar cells based on solution-processed semiconductor nanoparticles — colloidal quantum dots — have seen rapid advances in recent years. By offering full-spectrum solar harvesting, these cells are poised to address the urgent need for low-cost, high-efficiency photovoltaics.

Suntech Power is the world's largest producer of solar panels and has delivered more than 20 million photovoltaic panels to more than 80 countries around the globe. Nature Photonics spoke with Stuart Wenham, chief technology officer at Suntech Power, to find out more about its activities and visions.

Bio-inspired by the nano-architectures of iridescent Morpho butterfly scales, scientists have demonstrated a highly sensitive infrared detector that can efficiently upconvert mid-infrared radiation to visible iridescence changes.

Extreme ultraviolet attosecond pulses, which emerge from the interaction of atoms with intense laser fields, play a central role in modern ultrafast science and the exploration of electron behaviour. Recent work now shows that catastrophe theory can help optimize the properties of these pulses.

The demonstration of an in-fibre semiconductor photodetector with gigahertz bandwidth bodes well for the future development of hybrid fibre optoelectronics.

The intermediate-band solar cell is designed to provide a large photogenerated current while maintaining a high output voltage. Nanostructured materials and certain alloys have been employed in the practical implementation of these devices. This Progress Article reviews the range of different approaches and discusses how to resolve the remaining technical issues.

This Review summarizes recent progress in the development of polymer solar cells. It covers the scientific origins and basic properties of polymer solar cell technology, material requirements and device operation mechanisms, while also providing a synopsis of major achievements in the field over the past few years. Potential future developments and the applications of this technology are also briefly discussed.

This Review focuses on several recent promising innovations in the field of dye-sensitized solar cells. The key strategies for device engineering and dye design are illustrated, together with explanations as to how these factors affect the robustness and power conversion efficiency of the final device. The outlook towards the commercialization of dye-sensitized solar cells is also described.

By applying catastrophe theory to high-harmonic generation, researchers identify caustics relating to regions of spectral focusing and greatly enhanced field intensity.

Fabricating doped semiconductor layers and p–n junctions inside silica optical fibres allows the realization of a new breed of in-fibre optoelectronic devices, such as photodetectors with gigahertz bandwidths.

Researchers demonstrate that PBDTT-DPP, a semiconducting polymer with a low bandgap of 1.44 eV, allows tandem polymer solar cells to reach power conversion efficiencies of around 8.6%.

Using electro-optically generated frequency combs, scientists demonstrate radiofrequency photonic filters that can potentially provide simultaneous high stopband attenuation, fast tunability and bandwidth reconfiguration.

Inspired by thermal expansion and refractive index changes in the nanostructures of iridescent Morpho butterfly scales, scientists demonstrate upconverted mid-wave infrared detection with a temperature sensitivity of 18–62 mK and a heat-sink-free response speed of 35–40 Hz.

The application of catastrophe theory to high-harmonic generation is creating opportunities for optimizing the spectral intensity of extreme-ultraviolet light and characterizing attosecond pulses, explains Oren Raz from the Weizmann Institute of Science in Israel.

Photovoltaics is expected to provide the next generation of safe, secure, sustainable and affordable energy. The challenges now are to reduce costs and improve power-conversion efficiencies. This Focus Issue covers cutting-edge solar cell technologies such as polymer, dye-sensitized and intermediate-band solar cells, as well as advanced light-harvesting techniques based on plasmonics and quantum dots. Also included is an interview with the world's largest solar-cell manufacturer on the future of the photovoltaic industry.