Das Photovoltaik-Element

A photovoltaic cell converts light directly into electricity – using the so-called photoelectric effect. Here's a simple explanation of the principle: ☀️ Basic idea: Sunlight consists of tiny packets of energy (photons). When these hit a solar cell, they can set electrons in motion – and moving electrons are exactly what we call electric current. ⚙️ Structure of a solar cell Most solar cells are made of the semiconductor silicon. They have two layers: • n-layer (excess electrons) • p-layer (deficiency of electrons = "holes") An electric field exists between the two layers because they are separated (insulated) by a thin junction. 🔋 How electricity is generated (step by step): 1. Light hits the cell → The photons carry the energy that is important for us 2. The electrons in the silicon material are energetically excited → Valence electrons break free from their bonds in the silicon crystal 3. The electric field now "guides" the electrons toward the junction → (The p-n junction initially separated the charges) • If the energy of the electrons is high enough, they migrate across the junction to the n-side. 4. Current flow is generated → When a circuit is now closed, the free electrons flow through the wires to the load. → This is usable direct current (DC)!