Power Conversion Efficiency (PCE) is a characteristic value of solar cells and light emitting diodes in which the energy efficiency is expressed. The PCE value results from the ratio of the output power to the input power.
Inphotovoltaics, the input power depends on the solar irradiation and the output power is the sum of the short-circuit current, the unloaded output voltage and the fill factor. The latter is a dimensionless value for Q, which is >1.
The Power Conversion Efficiency (PCE) is given in percent. The value is strongly dependent on the silicon used. Amorphous silicon has the lowest PCE value. This is 8 %. The efficiency of polycrystalline silicon is between 15 % and 20 % and that of monocrystalline silicon between 20 % and 22 %. There are also solar cells made of copper indium selenide( CIS) with an efficiency of 12 % and gallium arsenide (GaAS) with an efficiency of 25 %.