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How to Make an Amorphous Solar Cell

Amorphous silicon solar cells are the most commonly used thin-film solar cell technology and are considered the best alternative to the more expensive, but also more efficient, crystalline solar technology. Both technologies rely on semiconductors (usually silicon-based) that capture energy from the sun, but amorphous photovoltaic cells have a less rigidly structured molecular distribution that allow for the stacking of multiple layers for greater efficiency.

Cost-effective methods of manufacturing panels made from these cells has proven elusive because amorphous cell production requires specialized machinery to deposit the layers of silicon evenly onto the cell's backing material, .

Things You'll Need

Backing material: glass, stainless steal, heat resistant plastic or specialized roofing tiles.
Superconductor gas like silane (SiH4)
Plasma-enhanced or hot wire chemical vapor deposition machine

Instructions

Creating Amorphous Solar Cells
- 1
  Choose what kind of backing material you'd like your solar cells to be on. The amorphous superconductor material, be it silicon or otherwise, is most commonly attached to glass or stainless steel but can also be mounted to flexible plastic (for a rollable solar panel) or to a specialized roofing tile.
- 2
  Once you've chosen your backing material, you will apply the superconductor layer to it either by a plasma-enhanced chemical vapor deposition (PECVD) or a hot-wire catalytic deposition system (HWCVD). Assuming you are creating a silicon-based cell, PECVD works by isolating the backing material in a chamber filled with silane (SiH4) and hydrogen gases (to increase homogeneity of the cell). High frequency radio frequency power is applied to the gas via electrode plates to create a highly ionized gas called a "plasma," which will excite the silane and cause it to decompose into its constituent silicon and hydrogen atoms. HWCVD works by similar principles, but instead of a plasma to excite the silane gas, it is a superheated metal filament that causes the silicon radicals to break off.
- 3
  Once the silane gas has been heated or excited in the PECVD or HSCVD systems, the silicon atoms deposit on the backing material such that three of the silicon atom's four bonding regions are covalently connected to other silicon atoms, while the fourth has a hydrogen atom (which gives the amorphous cell its flexibility). The completed product will be one large cell to which you can install other layers, depending on your plans for the solar cell.
- 4
  The highest efficiency amorphous solar panels, called "multijunction" cells, are composed of multiple layers of these amorphous solar cells made from a number of different superconductor alloys. The different layers each capture light waves of different wavelengths, thus increasing the spectrum and amount of light that will be absorbed and converted to power. Other enhancements, like a nonreflective layer, further increase the panels' efficiency, and a transparent conducting oxide film transfers electricity between the layers.

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