Doesn't have to total to 100% IR, Visible, and UV do not cover the entire EM spectrum, the sun puts out energy over a very broad range of frequencies.
--- Horace Heffner <[EMAIL PROTECTED]> wrote: > > On Jan 15, 2006, at 7:19 AM, > [EMAIL PROTECTED] wrote: > > > > http://www.photonics.com/todaysheadlines/article.asp?id=6070 > > > > > > "With this approach, we are well on our way to > power levels > > exceeding 100 watts per meter," he said. > > > Pretty amazing, though I have to wonder what "well > on our way" means. > > > > > One challenge for organic solar cells has been > the efficient > > capture and conversion of sunlight. Sunlight is > comprised of > > photons (particles of light) that are delivered > across a spectrum > > that includes invisible ultraviolet (UV) light, > the visible > > spectrum of colors -- violet, indigo, blue, green, > yellow, orange > > and red -- and the invisible IR spectrum. The > amount of incoming > > photons across the UV, visible and IR spectrums is > about 4, 5 and > > 45 percent, respectively. > > Looks like a typo above. Doesn't add up to 100 > percent. Anyway, > more important than the number of photons is the > amount of *energy* > (per area) incoming in the various bands. > > > The visible spectrum is commonly (i.e. for most > people) 400 to 700 > nm. See: > <http://www.factspider.com/vi/visible-spectrum.html> > > Percent solar constant at aircraft altitude: > > Lambda (nm) Cum % % Range > > 0 - 400 8.725 8.725 UV > 400 - 700 46.879 38.154 Visible > 700 - 100000 99.999 53.120 IR > > Derived from page 18-10 of the 74th Edition of The > CRC Handbook. > > Horace Heffner > > Merlyn Magickal Engineer and Technical Metaphysicist __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
