The plasma chambers suspend the silicon and the phosphorus or boron molecules in a gaseous state. This mixture is pushed into a chamber which has electrodes at the top and bottom. When the electrodes are charged an electric field is produced between them. The electric field removes some of the electrons from the mixture so creating a gas of positively charged ions, a plasma. A stainless steel or glass sheet with an indium/tin oxide layer is passed into the chamber and between the electrodes. The plasma-like gas deposits charged particles on to the uncharged surface of the steel or glass substrate. Depending upon the chemical nature of the gaseous mixture fed into the chamber, one of the three layers which make up the photovoltaic cell will be formed. The thickness of the layers depends on the speed at which the sub state passes through the chamber, and the size of the chamber.
An insulator or dielectric is a substance within which there are no mobile electrons necessary for electric conduction. However, when the voltage applied to such an insulator exceeds a certain value, then it breaks down and allows a heavy electric current (much larger than the usual leakage current) to flow through it. If the insulator is a solid medium, it gets punctured or cracked. The disruptive or breakdown voltage of an insulator is the minimum voltage required to break it down. Dielectric strength of an insulator or dielectric medium is given by the maximum potential difference which a unit thickness of the medium can withstand without breaking down. In other words, the dielectric strength is given by the potential gradient necessary to cause breakdown of an insulator. Its unit is volt/meter (V/m) although it is usually expressed in KV/mm. For example, when we say that the dielectric strength of air is 3 KV/mm, then it means that the maximum PD which one mm thickness of ...
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