Whenever a impurity is added to the semicondutor i.e. silicon or Ge

[amaresh92]

whenever a impurity is added to the semicondutor i.e. silicon or Ge ,why the impurity is chosen from group 13 and 15?why not from group 17 or 12 from periodic table?

 

[Wetmelon]

My guess is that it's more based on electrical properties of a particular substance rather than bonding properties or physical properties... and group 17 might bond too readily. But I'm certainly no expert

 

[Studiot]

Look at the crystal structure of the host matrix and then look for atoms that will fit.

 

[granpa]

now that you say that I remember having read it somewhere

 

[dlgoff]

Here's a couple pages about silicon, germanium and doped semiconductors.
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/sili.html#c1"
http://hyperphysics.phy-astr.gsu.edu/hbase/solids/dope.html"