InGaAs series-connected, tandem, MIM TPV converters

Thermophotovoltaic (TPV) tandem converter technology is being explored in an effort to improve the efficiency of TPV systems while maintaining high power densities. Series-connected (SC) tandem structures incorporate epitaxially grown 0.74 eV lattice-matched Ga/sub 0.47/In/sub 0.53/As and 0.63 eV lattice-mismatched Ga/sub 0.36/In/sub 0.64/As diodes. Structures have been grown using OMVPE and devices have been fabricated via wet-chemical processing. The 10-cell SC tandem MIM reported here produced 6.14 V in the open-circuit condition, 0.292 A/cm/sup 2/ in the short-circuit condition, and exhibited a fill factor of 67.6%. These values were measured at a cell temperature of 52/spl deg/C using a low emissivity /spl sim/1000/spl deg/C graybody illumination source. To our knowledge, these results are the first-of-a-kind for SC tandem MlMs.