Multi-terminal dual junction InGaP2/GaAs solar cells for hybrid system

The performance of two and three-terminal solar cells under 13-sun AM1.5G illumination is reported. The solar cells are comprised of monolithically grown InGaP
2
and GaAs single junction cells. The two-terminal device consists of single junctions in series. The three-terminal device structure comprises the single junctions independently interconnected by an InGaP
2
layer serving as the middle contact. Device optimization was based on modeling of the InGaP
2
top junction band gap for various spectral irradiance profiles. It was found that the optimal band gap combination for a 2.6eV filtered AM1.5G spectrum is achieved with 1.84eV and 1.43 eV for the top and bottom junctions, respectively. External quantum efficiency and illuminated current-voltage (I–V) measurements of the component two and three-terminal tandem cells are discussed.