A photoconductor's electrical properties go from insulating to conducting when it is exposed to light because,
A) light allows extra electrons to move out of the valence band giving the semiconductor a positive charge.
B) light allows extra electrons to move into the conduction band giving the semiconductor a negative charge.
C) light supplies the energy needed to move electrons from the valence band to the conduction band.
D) light lowers the energy of the conduction levels eliminating the energy gap.

Question

Quizplus · Accepted Answer

Light supplies the energy needed for electrons to move from the valence band to the conduction band, which is how photoconductors become conductive upon exposure to light. This transition allows for electrical conductivity as electrons can move freely in the conduction band.

A Photoconductor's Electrical Properties Go from Insulating to Conducting When