Production data on 0.55 eV InGaAs thermophotovoltaic cells

Low bandgap 0.55 eV (2.25 /spl mu/m cutoff wavelength) indium gallium arsenide (In/sub 0.72/Ga/sub 0.28/As) thermophotovoltaic (TPV) cells use much more of the long wavelength energy emitted from low temperature (<1200/spl deg/C) thermal sources than either Si or GaSb cells. Data are presented on a statistically significant number (2500) of these TPV cells, indicating the performance obtainable in large numbers of cells. This data should be useful in the design and modeling of TPV system performance. At 1.2 A/cm/sup 2/ short-circuit current, an average open-circuit voltage of 283 mV is obtained with a 60% fill factor. The peak external quantum efficiency for uncoated cells is 65% and is over 50% from 1.1 to 2.2 /spl mu/m. Internal quantum efficiency is over 76% in this range assuming an estimated 34% reflectance loss.