In a solar cell,semiconductors of the p-type and n-type are placed in contact with each other via a conducting wire.In order to generate an electric current,which of the following must be true?
A)An external battery must be attached
B)Light shining on the system will cause oxidation to occur
C)Light shining on the system must have enough energy to set electrons in motion from the n-type semiconductors to the p-type
D)Light shining on the system must have enough energy to set electrons in motion from the p-type semiconductors to the n-type

Question

Quizplus · Accepted Answer

When light shines on a solar cell, it excites electrons in the n-type semiconductor, causing them to move towards the p-type semiconductor. However, for an electric current to flow, the electrons must be able to move freely and this can only happen when they have enough energy to overcome the energy barrier between the two types of semiconductors. This is known as the "built-in potential" and is what separates the electrons in the n-type semiconductor from the holes (positively charged spaces) in the p-type semiconductor. Therefore, the light must have enough energy to move electrons from the n-type semiconductor to the p-type semiconductor for an electric current to be generated. No external battery is needed for this process. Option B is incorrect because light does not cause oxidation in a solar cell. Option D is incorrect because the electrons must move from the n-type semiconductor to the p-type semiconductor.

In a Solar Cell,semiconductors of the P-Type and N-Type Are