Photovoltaic Effect

When a light photon strikes a PN junction, it initiates a fascinating chain of events that lead to the flow of current through an external circuit. Let's delve into the intricate process that occurs when this phenomenon takes place.

What happens when a light photon strikes a PN junction?

Upon impact, the light photon imparts energy to the electrons in the PN junction, causing some of them to break free from their atomic bonds. These liberated electrons then migrate towards the junction, creating a potential difference between the two sides of the junction.

How does the potential difference lead to current flow?

The potential difference established by the movement of electrons across the PN junction creates an electric field. This electric field exerts a force on the electrons, propelling them towards the opposite side of the junction. As a result, a current is induced in the external circuit connected to the PN junction to neutralize the potential difference.

Why is this phenomenon significant?

The generation of current in a PN junction due to the impact of light photons is a fundamental principle underlying the operation of various optoelectronic devices, such as solar cells and photodiodes. Understanding this process is crucial for the development of advanced technologies that harness light energy for various applications.

By comprehending the intricate interplay of light photons, electrons, and potential difference in a PN junction, researchers and engineers can continue to innovate and create cutting-edge devices that rely on the conversion of light into electrical energy.