Silicon is used for 2 reasons...
1)Cheap as sand on a beach...germanium and Gallium Arsnide are expensive materials to start with and less developed technologically.
2)Silicon "naturally" grows Silicon Dioxide Si02, which is the material required to make the gates/gate capacitors. All materials...
Voltage has no bearing on size cause wires/cables are rated in Amps/cm^2. Like a stun gun that has 1,000,000Volts and 30something gauge wires...this is because the amperage is like .000001 amps. Some really high power lines are rated in Power/cm^2 but this is only for appilcations the govt. can...
Hey all you need to evaluate the wire gauge for is Amps...the freq. is not relavent unless doing some communication signal design. So go to:
http://www.bnoack.com/index.html?http&&&www.bnoack.com/data/wire-resistance.html
Click (CABLING) on left scroll menu
Click (POWER CABLE AMPERAGE) and...