Let me preface this with a warning that I am no expert; I simply saw a graduate student's research and would like to see a discussion of this. He was working (At UT Knoxville if anyone is interested) on a way to make chlorophyll more efficient for use in solar panels. Basically, this causes a concentration gradient of H⁺ ions, starting off the ETC, just like High school biology teaches. However, the problem he was working with is the fact that Chlorophyll isn't very efficient. As anyone looking at a plant can see, Chlorophyll reflects much of the light in the "Green" spectrum (Roughly 560-520nm) and absorbs light fairly well in the red and blue wavelengths. (700-635nm, and 400-490nm respectively) His work was to make a protein absorb more of the visible light spectrum, and therefore produce more energy. My question is, why not aim for ultraviolet or the higher frequency forms of light? Would the more energetic photons not be better for starting the ETC? If anyone was wondering, his setup involves his protein upon a thin gold plate, covered with a conductive, transparent material that I do not remember the name of. Discussing this with a friend, he mentioned that at the earth's surface, there's generally more visible light available than ultraviolet, so it would be more efficient to capture what is more abundant. However, I would like some additional opinions.

Not at all area, but my guess would be that the sun just puts out much more radiation in the visible wavelengths than higher energy wavelengths such that any gain in more energy from a photon is offset by having far fewer photons.

I'm no expert too but I would speculate that the sun is putting out a whole lot of radiation outside of the visible spectrum, the earth's atmosphere is blocking most of it leaving visible spectrum and some UV.

1 hour ago, koti said:

I'm no expert too but I would speculate that the sun is putting out a whole lot of radiation outside of the visible spectrum, the earth's atmosphere is blocking most of it leaving visible spectrum and some UV.

I think most of the UVC and higher gets stopped by the upper atmosphere and what there is can get stopped by polycarbonates and glass. The more energetic a photon is, the greater the chance of it interacting with something, which limits its distance.

Edited May 16, 20187 yr by StringJunky