Growth of InGaAsP solar cells and their application to triple-junction top cells used in smart stack multijunction solar cells

The authors report on high-quality InGaAsP (1.61–1.65 eV) solar cells grown on a GaAs substrate; their study is the first to grow these using solid-source molecular beam epitaxy (SS-MBE). A temperature of 430 °C was found to be suitable for the growth of the InGaAsP solar cells. The properties of these InGaAsP solar cells were found to be better than those of AlGaAs solar cells that had the same bandgap energy, and it was found to be suitable for use as the second cell in a triple-junction top cell used in a smart stack multijunction solar cell. The authors also developed an InGaP/InGaAsP/GaAs solar cell and found that it had an impressive open-circuit voltage of 3.16 V. This result indicates that high-performance InGaP/InGaAsP/GaAs triple-junction solar cells can be fabricated using SS-MBE.