Monolithically interconnected InGaAs TPV module development

This paper describes the status of development of an indium gallium arsenide (InGaAs) monolithically-interconnected module (MIM) for thermophotovoltaic (TPV) energy conversion applications. The MIM structure features series interconnected InGaAs sub-cells on an insulating indium phosphide (InP) substrate, with a rear-surface infrared (IR) reflector. Motivations for developing the MIM structure include: reduced resistive losses; higher output power density; improved thermal coupling; and, ultimately, higher system efficiency. An optical model has been developed, free carrier absorption coefficients have been measured and a prototype MIM device has been demonstrated. A rear surface IR reflector has been developed with /spl sim/98% reflectance in the sub-bandgap (>1.7 /spl mu/m) region.