Semiconductor Diode

A semiconductor diode is a fundamental component in photovoltaic cells and thus a central part of solar panels. It consists of two differently doped semiconductor layers, usually silicon, that form a pn-junction.

Functionality in Photovoltaics:

• Generation of charge carriers: When light strikes the solar cell, energy is transferred to the electrons in the semiconductor layer. This allows them to detach from the atom and become free charge carriers (electrons and holes).
• Direction of charge carriers: The electric field in the pn-junction drives the freed electrons into the n-doped region and the holes into the p-doped region.
• Current flow: At the outer contacts of the solar cell, this separation of charge carriers creates an electrical voltage. When a load is connected, an electric current flows.

Importance for Photovoltaics:

• Clear current direction: The diode ensures that the generated current can only flow in one direction. This is essential for utilizing the electrical energy from the solar cell.
• Prevention of reverse current: At night or in low sunlight conditions, a solar cell can also function as a load. The diode prevents the generated current from flowing back from the grid into the solar cell.

In summary, the semiconductor diode is the heart of a solar cell. It converts light energy into electrical energy and enables its utilization.

Relevant keywords: photovoltaics, solar cell, pn-junction, electrical voltage