$GaAsN∕InAsN$ superlattice based multijunction thermophotovoltaic devices

Quantitative modeling of the performance of a single and multijunction $p(InGaAs)-i(superlattice)-n(InGaAs)$ device lattice matched to InP utilizing a $GaAsN∕InAsN$ superlattice structure is performed, and the results are compared quantitatively with the bulk metamorphic InGaAs counterpart devices. Optimized band gaps of the subcells of multijunction device are estimated by finding the optimal current to provide the maximum power through the series-connected double, triple, and quadruple junction cells for $1350K$ blackbody radiation as an incident flux. The output power-density of the four junction superlattice device is shown to be $∼1.8W∕cm2$⁠, for the fixed $0.74eV$ first cell band gap. Lattice matching to InP substrate and the availability of various band gaps from the $GaAsN∕InAsN$ structure are emphasized for the use in multijunction thermophotovoltaic device producing higher output power densities in comparison to the bulk InGaAs based devices.