. "Multi-junction (MJ) solar cells are solar cells with multiple p\u2013n junctions made of different semiconductor materials. Each material's p-n junction will produce electric current in response to different wavelengths of light. The use of multiple semiconducting materials allows the absorbance of a broader range of wavelengths, improving the cell's sunlight to electrical energy conversion efficiency.Traditional single-junction cells have a maximum theoretical efficiency of 34%."@en . .