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National Net Zero Policies

Solar Photovoltaic Technology: Harnessing Sunlight

Discover how photovoltaic cells convert sunlight into electricity. Explore the physics, materials, and efficiency limits of solar PV technology.

How Solar PV Works

Solar photovoltaic (PV) technology converts sunlight directly into electricity using the photovoltaic effect. When photons from sunlight strike a semiconductor material, they can excite electrons, creating an electric current. This process happens at the atomic level and depends on the semiconductor's properties, particularly its band gap energy.

The efficiency of solar cells depends on matching the semiconductor's band gap to the solar spectrum. Materials with different band gaps absorb different wavelengths of light, and the choice of material represents a fundamental trade-off between efficiency and cost. Understanding these physics principles is crucial for designing better solar technologies.

The Photovoltaic Effect

Discovered by Alexandre Edmond Becquerel in 1839, the photovoltaic effect occurs when light photons transfer their energy to electrons in a semiconductor, allowing them to flow freely and generate electricity. This quantum mechanical process is the foundation of all solar PV technology.

Interactive Solar Cell Physics Simulator

Solar Cell Materials

Selected: Silicon (Si) - Most common PV material
Photon Energy Control
0.5 eV (Infrared)4.0 eV (Ultraviolet)
-20°C80°C
Energy Analysis
Band Gap:1.1 eV
Can Absorb:Yes
Useful Energy:2.1 eV
Thermal Loss:0.4 eV
Efficiency:44.0%
Step 1 of 7

Photon Absorption Process

Step 1 of 7
Silicon Semiconductor
1.1eV
Photon (2.5eV)
Photon approaches the solar cell...
Theoretical Maximum
33.7%
Shockley-Queisser limit for single-junction cells
Commercial Record
26.1%
Multi-junction concentrator cell (2023)