Doping introduces allowed energy states within the band gap of the material, and these energy states are very close to the energy band that corresponds to the dopant type.
From the Wikipedia article on doping in semiconductors:
[For example] electron donor impurities create states near the conduction band while electron acceptor impurities create states near the valence band.
The gap between these energy states and the nearest energy band is usually referred to as dopant-site bonding energy or E(b)and is relatively small.
For example, the E(b) for Boron in Silicon bulk is 0.045 eV, compared with silicon's band gap of about 1.12 eV.
Because E(b) is so small, the room temperature is sufficient to thermally ionize practically all of the dopant atoms and create free charge carriers in the conduction or valence bands.
From QuestionHub.net:
the delocalized charges "spend most of their time" around silicon, such that locally speaking silicon becomes charged (?).
So the above picture is not correct as one does not get silicon to be charged the charges are either in conduction band or valence band and can act only when some contact potential drives them to diffuse.
Another effect of Dopants is that they shift the energy bands relative to the Fermi level.
From Wikipedia again:
The energy band that corresponds with the dopant with the greatest concentration ends up closer to the Fermi level.
Therefore if one stacks layers of materials with different properties it leads to various electrical features induced by band bending.
For example, the p-n junction's properties are due to the band bending in contacting regions of p-type and n-type material.