Solar Cell Material Efficiency Simulator
Solar Spectrum and Band Gap Efficiency
This simulation shows how different semiconductor materials interact with the solar spectrum. The vertical line represents the material's band gap energy (Eg). Photons with energy above Eg can be absorbed to generate electricity.
Silicon (Si)
Band Gap: 1.1 eV
Efficiency: ~20%
Common, inexpensive, but lower absorption coefficient
Gallium Arsenide (GaAs)
Band Gap: 1.53 eV
Efficiency: ~29%
High efficiency, excellent match with solar spectrum
Cadmium Sulfide (CdS)
Band Gap: 2.4 eV
Efficiency: ~10%
Too high band gap misses most solar spectrum
Lead Sulfide (PbS)
Band Gap: 0.4 eV
Efficiency: ~5%
Too low band gap causes thermalization losses
