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Capturing Solar Power With Antennae
necro81 writes "Researchers at the University of Missouri and the Idaho National Laboratory have demonstrated a new method of capturing solar power. Rather than using semiconductors to capture photons of sunlight, they fabricated small coiled antennae (several um square) that resonate with the wave nature of light. The antennae are tuned towards midrange infrared light (5-10 um), which is abundant on our cozy-warm Earth — even at night. They also demonstrated a way to imprint these coils on a substrate, like how CDs or vinyl records are produced, but could be scaled to roll-to-roll mass production. The usual caveat applies: it may be 5-10 years until this could hit the market."
Antennae are for bugs.
Haida Manga
What are they using to rectify the signal to convert to DC? The antenna is neat - but not at all surprising, its size should just scale with wavelength. You could make a 125nm long antenna that would resonate with visible light (well withing the resolution of existing lithography). The problem is how to convert the 100THz signal you get to a DC signal. You need a fantastically fast diode.
If they have managed this, that would be an impressive achievement. The fastest diodes I am aware of are around 1THz, but its well outside my field and there might be something faster out there
BTW: the efficiency isn't all the impressive. For single frequency light, conventional solar cells can be quite efficient (~80%???), but they don't do will with broad thermal light (like sunlight). The photons that are less than a band-gap don't do anything, and the ones above a bandgap waste any excess energy.
Phrenologically speaking, your entire post is really lumpy. From a cooking standpoint, your pot is cracked. And scientifically speaking... well, why bring science into it now?
I've fallen off your lawn, and I can't get up.
I think you see the problem - I *am* in a related field and I certainly don't know of any practical or efficient way to rectify it. I can think of absurdly inefficient ways, but we already have a bunch of those.
What are they using to rectify the signal to convert to DC?
Unobtainum diodes. They don't actually know how to do that.
Terahertz diodes do exist. Low-cost, high-efficiency, integrated terahertz diodes, no. But as work proceeds on terahertz electronics, someone may solve that problem. Each nanoantenna needs its own nanodiode, so the diodes have to be fabricated on the substrate with the antenna, which complicates the fab problem. The enthusiasm about roll-to-roll low cost fabrication in the article is premature. We'll probably see this working first on a wafer, and it may not be cheap.
Even if it's expensive, there's an initial market for satellite power panels. The performance improvement would be worth it.