Lecture
This lecture covers the concept of free electrons and holes in semiconductors, explaining how charge carriers can be manipulated to generate electric fields. By introducing dopants like phosphorus, free electrons are created in the conduction band, increasing conductivity. Conversely, by introducing acceptors like boron, holes are created in the valence band, allowing the movement of positive charges. The concentration of dopants determines the conductivity change, with electrons or holes being the dominant charge carriers.