Solar cell simplyfied

A solar cell is a photoelectric converter. It converts photons into electrical energy.

Wp (Watt Peak)

maximum electrical output power under standard illumination

Example for Germany 10 kWp

Electricity Generation: Summary

The solar spectrum corresponds approximately to a black body radiation with a temperature of 5800 K

The power by solar irradiation at AM 1.5 is 1 kW/m2

In central Europe (Germany), PV modules with 1 kWp can produce ≈1000 kWh of electric energy per year

The contribution of solar cells to electricity generation continuously increases all over the world

Current-Voltage Dependence

Working Principles: Summmary

A solar cell converts light into electric energy by separation of electron-hole pairs

The current-voltage curve of the illuminated diode corresponds to that of the non-illuminated diode shifted on the current axis by the photocurrent (if the photocurrentis independent on voltage)

The efficiency of the solar cell is given by the product of the open circuit voltage, theshort circuit current and the fill factor, divided by the incident light intensity

The photocurrent corresponds to the number of absorbed photons and decreaseswith the band gap of the semiconductor

The photovoltage of a p-n diode solar cell increases linearly with the band gap

The theoretical efficiency (Shockley-Queiser-limit) has a maximum of 30% for bandgaps of 1.2-1.5 eV

Last changed2 years ago