Butterfly Wing and Thin Film Solar Cell

Presumably, there would need to be an AR coating on a flat layer above??? Or someone better get started on the research of how a butterfly cleans its wings.

Butterflies live about how long?

Eastern Black Swallowtail (not the butterfly in the earlier link, and not totally black as you can clearly see), lives on average about 2-3 generations in the summer. The Pupae overwinter. All else I could find was about 2 weeks. Monarchs may live about 1 year and no longer.

Yes the butterfly effect...I've heard of it...

We were not talking about the Lorentz equation, strange attractors (odd), or chaos theory, or the Logistic iteration.

. We were talking about sunshine , and the ability to absorb it. Does this factor in somehow? Perhaps it could in designing better absorbers???

Yes the optofluidic fresnel lens combo....

Now you went and said another set of those high dollar engineering style words.

I just love it when you get all graphic like that.

Enhanced version....

"Ion gel as a high-capacitance dielectric for low-cost and low-voltage electrowetting applications. The ion gel offers a 2 to 3 order higher capacitance (c ≈ 10 μF/cm2) than that of conventional dielectrics such as SiO₂ and Al₂O₃, while being fabricated through a simple low-cost spin- or dip-coating process. Such an extremely high capacitance results from the nanometer-thick electric double layer (EDL) capacitor formed by the compact accumulation of free counter-ions at the interface under an applied electric field. Thus, the capacitance of the ion gel layer is thickness-independent."

"A schematic of the liquid prism filled with two immiscible liquids. Four prism sidewalls are assembled and dip-coated with a dielectric (ion gel) and a hydrophobic layer. An electrowetting effect adjusts the prism apex angle φ by applying bias voltages to the left and right sidewalls, separately. Due to the refractive index difference (n_air ≠ n₁ ≠ n₂) of each medium, incoming light is effectively steered without any bulky mechanical moving components."

http://blog.nus.edu.sg/ofes/research/

I had to go to the link to figure out that last figure. That apparently has to do with droplet manipulation

(i.e. - taking micro-fluidic forces to bear in preparing micro-droplets out of a stream for biological sampling or the like.)

People always act as if this is some magical new discovery.

The laws for Fresnel surface reflectance have been know for a really long time. Ditto the laws of constructive and destructive interference of waves.

The typical reflectance loss from a surface is around 4%. An antireflection (AR) coating can reduce this to less than 0.2%, but the added cost of the coating has to be weighed against the miniscule 3 to 4% gain in power. And this presumes that the solar cell surface remains pristine clean. A fine layer of grime could result in the AR coated panel having less power output than an uncoated panel.

And this all has to be weighed against the environmental impact of solar panels, which is significant. (Don't get me wrong; in the proper location solar panels are fantastic.)

Butterflies are free.

Solar panels aren't.

I suppose we will have to have disposable and recyclable solar panels then, to make everyone happy, just wad the thing up when done, and put it in the dust bin, and move on.

OR, we could come up with something entirely new, such as a way to clean these surfaces using something like plasma state (not really hot plasma, but definitely a glowing ionic gas), such as has been used with delicate optics in the past. Oh, snap, then it wouldn't be new at all, now would it?

No problem, that's why we have robots....solar powered robots

haha...all we need here is a cat supervisor....

Gosh, people think of everything these days! It is the mother time of invention!

I think the effect can probably be tuned to advantage, especially in thin-film structures where light trapping becomes important because the absorber layers are relatively thin.

What makes these butterfly-type surfaces interesting is that the benefit is not just lower reflection. The nano-scale textures can also increase scattering and extend the optical path inside the active layers, which improves the probability of absorption before the light escapes.

In practice though, the harder problem is usually fabrication repeatability rather than the optical theory itself. Once you try to reproduce these kinds of textured surfaces over larger substrate areas, small variations in deposition conditions, drying behavior, or layer morphology can noticeably change the optical response.

Partially random structures may actually help in some cases because they broaden the absorption behavior over a wider wavelength range instead of favoring only narrow bands.

I suspect the best performance would come from combining controlled surface texturing with good refractive-index matching and stable thin-film deposition processes, rather than relying on a single “ultra-black” surface effect alone.

I think the problem is not being able to manufacture large area thin films. The films could be suspended in layers and tuned for different WL. And small air gaps would help with cooling.

It appears most work has being spraying a layered film or using coatings. With great results. I read some of these films are active films. Film properties can be switched and modulated with small currents.

I know nothing about it, only what I’ve read.

I wonder if an antenna could be modulated with a coating? And blink a carrier. And if so, would it have side-bands? The carrier is never modulated before emission. Knuck knuck.

And I have been waiting many years for a few sheets of graphene.