114% quantum efficient solar cell - in the lab

[techntrek]

Mike if you lent out money at 10% per month what is the per annum rate??

Simple or compound?

[john p]

Its not relevant to the question. .As there is no amount of money given .therefor its only the percentage figure asked.

[techntrek]

Completely relevant, thus the difference between rate and effective annual percentage rate on loan documents.

[bmet]

what this may do is just allow a pv to be made for the lower and mid infrared ranges that will not respond as well to visible light. in essence, it's a trade off on wavelength and will not necessarily collect any more power than present technology.

And what happens to the glare study? Would these panels reflect low and mid infrared waves to a degree that they would confuse insects who see in these ranges? Is reflected infrared going to cause sunburn, interfere with security cameras, assist night-vision glasses, or screw with remote controllers in it's footprint? There are so many infrared devices in the general public, that panels may inadvertently cause electronic dead spots instead of warped vinyl siding.

[Joe_B]

Do they get colder when the sun shines on them?

[niel]

nobody said the panels would reflect the infrared and they do that now anyway to one degree or another like most things that are shiny or reflective. it's irrelevant.

as to insects, well i just haven't asked any of them lately if they are getting confused. have you asked them and if so please tell us what they said?

it is true that reflected infrared can warm you up, but the tans are from the other side of the light spectrum called uv.

all of the items you list take advantage of ir at night and wouldn't affect them detrimentally regardless.

[nsaspook]

what you guys may be missing here is that an antenna is a narrow band device, aka resonant. when it becomes a working development it may only work well in a narrow part of the spectrum. many see this type of curve already on pvs where it rises toward the smallest wavelength of infrared spectrum where it just about enters into visible light and then may start back down again in its response from there. what this may do is just allow a pv to be made for the lower and mid infrared ranges that will not respond as well to visible light. in essence, it's a trade off on wavelength and will not necessarily collect any more power than present technology.

It's pretty easy to make wide-band (~10:1) unity gain antennas with at normal RF frequencies. The same principle can be used with light with shaped feed elements.
http://en.wikipedia.org/wiki/Discone_antenna
http://classes.yale.edu/fractals/pan...lAntennas.html

[niel]

yes, i'll agree that some antenna designs may work well enough to overcome the narrowbandedness to some degree, but it will still be a resonant type thing. remember the multi-layered pvs that responded to various wavelengths? that was a similar idea.

[nsaspook]

Yes, Tandem PV junction cells are one way to bypass the http://en.wikipedia.org/wiki/Shockley–Queisser_limit

The problem with direct photon conversion is not really the antenna system, it's the (quantum
mechanical tunneling) diode needing to work at 150Thz with high efficiency that's the tough nut to crack.