Comment Re:Really? (Score 1) 719
The factor of 500 refers to the absorption only, not to conversion. It is perfectly imaginable to increase the absorption coefficient by such a factor.
The absorption coefficient of Silicon itself ranges from zero to 10^7 depending on the wavelength considered. See here http://www.ioffe.ru/SVA/NSM/Semicond/Si/Figs/145.gif
A factor of 500 is easily within reach when using other semiconductors with a direct bandgap (Si is indirect). InGaN would be such a material. It could cover the entire spectral range from IR to UV depending on composition.
