[sdiy] Charge diffusion conceptual confusion

[David]

I am trying to understand some underlying concepts in semiconductor theory.

First, here's my basic understanding:

The idea behind doping a semiconductor is to allow the creation of free
electorns/holes without breaking an existing covalent bond in the crystal
structure. P type dopes with an atom lacking an electron so in the lattice,
there is a partial covalent bond, but no extra free electron to balance it,
so there is an excess "hole". Vice versa for an N type. You use an element
with an extra electron so you get a full covalent bond, but an extra
electron.

That make sense. 

Now, my problem. In an N type, there are literally free electrons which can
move and drift and that's easy for me to conceptualize. But, in a P type,
the holes are derived from the doping element which is bound in the lattice.
These holes can be filled/emptied, but they can't move. They are tied to the
doping element which is bound in the lattice. What holes are moving? Do the
bonds in Si to Si atoms in the lattice break to allow an electron to move
into a doped hole?  If so, I can see that. The holes associated with the
doping element get filled from electrons from adjacent Si to Si bonds. The
hole moves through the entire lattice, not just where a doping atom is.
Maybe I just answered the question...

Lastly, I can grasp the concept of electrons flowing in a conductor or
semi-conductor. But, holes don't "flow" in a conductor, right? So, don't the
holes just stay in the semiconductor?

Maybe I should stick to Lagrangian mechanics...

David