The last development in III-V multi-junction solar cells

Multi-junction solar cells fabricated from III-V semiconductor materials exhibit high efficiencies matched by no other existing photovoltaic technology. Multi-junction solar cells are composed of 3 layers of material that have different band gaps. The top layer has the largest band gap while the bottom layer has the smallest band gap. This design allows less energetic photons to pass through the upper layer(s) and be absorbed by a lower layer, which increases the overall efficiency of the solar cell. One important design consideration is that the photocurrent generated in each layer must be the same since the layers are connected in series. In addition, the band gaps of each layer should differ by approximately equal energies so that the spectrum of incident radiation is most effectively absorbed.