An isothermal etchback-regrowth method for high-efficiency Ga/1-x/Al/x/As-GaAs solar cells

High-efficiency p-Ga(1-x)Al(x)As, p-GaAs, n-GaAs solar cells are made by isothermally soaking n-GaAs substrates in an undersaturated Zn-doped Ga-Al-As melt. This one-step growth procedure produces a graded band gap p-Ga(1-x)Al(x)As layer 0.2-0.4 micron thick. Efficiencies of 18.5% AM0 and 21.9% AM1 have been measured.