New Scientist -- Solar cells aiming for full spectrum efficiency

Solar power is set for a boost with the help of a material that can soak up energy from almost all of the Sun's spectrum. It should allow solar cells to jump in efficiency from today's best of 30 per cent to 50 per cent or higher.

Because it uses very pure material, indium gallium nitride (InGaN), that is very expensive to produce it will be some time before this is commercially available.