Question About Semi-Conductor

[newbie2k6]

When pure semi conductor(intrinsic) is doped with trivalent elements, p type semi conductor is formed(in which the concentration of holes is greater than free electrons) and when pure semi conductor is doped with pentavalent elements,n type semi conductor is formed(in which the concentration of free electrons is greater than holes).

 

Now My question is that which of these following condition is true about n-type and p-type semiconductors and Why?:hihi:

 

1.Concentration of holes in p-type = concentration of free electrons in n type

2.Concentration of holes in p-type < concentration of free electrons in n type

3.Concentration of holes in p-type > concentration of free electrons in n type

[Qfwfq]

The third and only the third is correct.

 

P-type means that holes are the majority carrier. You might take it as a definition, you might also need to know how to work out all the consequences in the working of devices having junctions between n-type and p-type.