Recent improvements in large area, high efficiency, monolithic interconnected modules (MIMs) represent a significant step in the development of thermophotovoltaic (TPV) technology for various power producing applications. The MIM architecture with transmissive integrated spectral control offers a desirable high‐voltage, low‐current output, front‐side contacts for simplified packaging, high spectral utilization due to a metallic, highly reflective and specular back surface reflector, and a practical method for scale‐up to full wafer devices. The n/p/n MIM TPV devices described in this work utilize a tunnel junction and a double heterostructure for improved performance. Lattice‐mismatched 0.6 eV, epitaxially grown InGaAs diodes form the power‐producing element. A power conversion efficiency of 20.6&percent; and a power density of 0.90 W/cm2with a silicon carbide radiator operating at 1058°C is achieved for a 4 cm2(die area) TPV cell operating at 26.7°C. © 2003 American Institute of Physics