Comparison of Al/sub 0.51/In/sub 0.49/P and Ga/sub 0.51/In/sub 0.49/P window layers for GaAs and GaInAsP solar cells

Two window layer materials, Al/sub 0.51/In/sub 0.49/P (E/sub g/=2.3 eV) and Ga/sub 0.51/In/sub 0.49/P (E/sub g/=1.88 eV) were compared for gas-source and solid-source MBE grown GaAs and Ga/sub 0.84/In/sub 0.16/As/sub 0.68/P/sub 0.32/ (E/sub g/=1.55 eV) solar cells. Due to the wider band-gap of Al/sub 0.51/In/sub 0.49/P, the increased spectral response was observed for both GaAs and Ga/sub 0.84/In/sub 0.16/As/sub 0.68/P/sub 0.32/ material based solar cells. In the case of the GaAs cells, the short-circuit current density was observed to increase from 32.5 mA/cm/sup 2/ to 34.4 mA/cm/sup 2/ with the Al/sub 0.51/In/sub 0.49/P window layer at AM0. Similar improvement was observed for the Ga/sub 0.84/In/sub 0.16/As/sub 0.68/P/sub 0.32/ solar cells.