Multijunction photovoltaic cell. Multi-junction solar cells are solar cells with multiple p-n junctions made of different semiconductor materials.
Each material's p-n junction will produce electric current in response to a different wavelength of light. A multi-junction cell solar cell will produce electric current at multiple wavelengths of light, increasing the conversion efficiency of the no-cost solar light power to usable electric power. Traditional single-junction cells have a maximum theoretical efficiency of 34%. Theoretically, with an infinite number of junctions, multi-junction cell efficiency would be 87% under highly concentrated sunlight. Solar Market Research and Analysis. Morgan Solar.