Semiconductors are more effective than metals as converters of solar radiation into electricity because
A)it is easier for the atoms of a semiconductor to absorb solar energy and to move from place to place within the solid,thereby conducting electricity.
B)the energy contained in sunlight gives the valence electrons in the semiconductor atoms the extra energy they need to "flow" throughout the solid.
C)metals melt much too easily under direct sunlight and,as liquids,lose their ability to conduct electricity.
D)solar radiation has sufficient energy to knock electrons completely off the metal surface,making it impossible for the electrons to "flow" from atom to atom and conduct electricity.

Question

Quizplus · Accepted Answer

Semiconductors have a specific property called a band gap, which is a range of energy levels that electrons can exist in. When a photon of sunlight (containing energy) hits the semiconductor, it excites an electron in the valence band (lower energy level) to the conduction band (higher energy level), creating a free electron and a "hole" in the valence band. This free electron can move freely through the semiconductor to create an electrical current. In contrast, metals do not have a band gap, meaning that electrons in the metal have already reached the conduction band and can move freely throughout the metal without the extra energy from sunlight. Therefore, semiconductors are more effective than metals as converters of solar radiation into electricity.

Semiconductors Are More Effective Than Metals as Converters of Solar