[amor de cosmos]

ASU, Georgia Tech Create Breakthrough for Solar Cell Efficiency
New atomic layer-by-layer InGaN technology offers perfect crystal
Released: 10/25/2013 2:00 PM EDT
Source Newsroom: Arizona State University College of Liberal Arts and Sciences

Newswise — Did you know that crystals form the basis for the penetrating icy blue glare of car headlights and could be fundamental to the future in solar energy technology?

Crystals are at the heart of diodes. Not the kind you might find in quartz, formed naturally, but manufactured to form alloys, such as indium gallium nitride or InGaN. This alloy forms the light emitting region of LEDs, for illumination in the visible range, and of laser diodes (LDs) in the blue-UV range.

Research into making better crystals, with high crystalline quality, light emission efficiency and luminosity, is also at the heart of studies being done at Arizona State University by Research Scientist Alec Fischer and Doctoral Candidate Yong Wei in Professor Fernando Ponce’s group in the Department of Physics.

In an article recently published in the journal Applied Physics Letters, the ASU group, in collaboration with a scientific team led by Professor Alan Doolittle at the Georgia Institute of Technology, has just revealed the fundamental aspect of a new approach to growing InGaN crystals for diodes, which promises to move photovoltaic solar cell technology toward record-breaking efficiencies.

http://www.newswise.com/articles/asu...ell-efficiency

Scientists' new approach improves efficiency of solar cells
Posted on 24 October 2013

An international team of scientists, led by researchers from the Universities of York and St Andrews, has developed a new method to increase the efficiency of solar cells.

The new approach achieves highly efficient broad-band light trapping in thin films, with more light captured in the film in order to maximise absorption and electricity generation.

The research, which is reported in Nature Communications, also involved scientists from Sun Yat-sen University and the GuangDong Polytechnic Normal University, China, and IMEC (Interuniversity MicroElectronics Center), Leuven, Belgium.

The new method builds on research into a class of materials known as quasi-crystals, which offer advantages in terms of the spectrum of light they are able to capture. However, the problem with these structures is that their properties are difficult to tailor towards specific applications as they lack the design tools available with periodic structures such as regular gratings.

To solve this problem, the researchers created a new structure called a quasi-random structure, which combines the rich spatial frequencies associated with quasi-crystals with the high level of control afforded by periodic structures.

http://www.york.ac.uk/news-and-event...h/solar-cells/