Solar technology is constantly evolving. Pioneers in the industry have contributed a great deal in innovation, advancing what we think we know about solar technology, into so much more! In this article, we introduce you to Hairy Solar Panels… Missed out on previous articles in the series? Catch up now…

Part 1 – Solar Glass

Part 2 – Thin Film Solar Panels

Part 3 – Perovskite Solar Panels

Part 4 – Coloured Solar Panels

Part 5 – Hairy Solar Panels

hairy solar panels

What are hairy solar panels?

Using arrays of long, thin silicon wires embedded in a polymer substrate, a team of scientists from the California Institute of Technology (Caltech) created a new type of flexible solar cell that enhances the absorption of sunlight and efficiently converts its photons into electrons. The solar cell does all this using only a fraction of the expensive semiconductor materials required by conventional solar cells.

How are these panels produced?

Hairy solar panels are produced with the help of nanotechnology by using light absorbing nanowires on carbon-nanotube fabrics. These nanowires have a cylindrical structure with a diameter of about a 10000th of a human hair.

The anatomy of hairy solar panels

Each wire or ‘hair’ on a panel measures between 30 and 100 microns in length and only 1 micron in diameter. In terms of area or volume, just 2% of it is silicon, and 98% is polymer.

While these arrays have the thickness of a conventional crystalline solar cell, their volume is equivalent to that of a two-micron-thick film. Or to put it in another way, there is a lot of empty space in there.

Since the silicon material is an expensive component of a conventional solar cell, a cell that requires just one-fiftieth of the amount of this semiconductor will be much cheaper to produce.

diagram 2
Photomicrograph of a silicon wire array embedded within a transparent, flexible polymer film.

How efficient are hairy solar panels?

The light-trapping limit of a material refers to how much sunlight it is able to absorb. The silicon-wire arrays absorb up to 96 percent of incident sunlight at a single wavelength and 85 percent of total collectible sunlight. What’s most important in a solar cell is whether that absorption leads to the creation of charge carriers.

The silicon wire arrays are able to convert between 90 and 100 percent of the photons they absorb into electrons. High absorption plus good conversion makes for a high-quality solar cell.

The key to the success of these solar cells is their silicon wires, each of which is independently a high-efficiency, high-quality solar cell. When brought together in an array, however, they’re even more effective, because they interact to increase the cell’s ability to absorb light.

Light comes into each wire, and a portion is absorbed and another portion scatters. The collective scattering interactions between the wires make the array very absorbing.

Diagram 4
This is a schematic diagram of the light-trapping elements used to optimize absorption within a polymer-embedded silicon wire array.

Spend less green to go green

The composite nature of these hairy solar cells means that they are also flexible. Having these be complete flexible sheets of material is important as flexible thin films can be manufactured in a roll-to-roll process, an inherently lower-cost process than one that involves brittle wafers, like those used to make conventional solar cells.

Why hairy solar panels?

Visually striking, highly efficient at carrier collection and highly absorbing.

 

Solar technology is indeed taking leaps and bounds.

Consider solar for your business or facility. CHAT to our experts now!

 

Source:

https://blog.thesietch.org/2010/02/23/hairy-solar-cells-cheap-efficient-potentially-revolutionary/