  Here we investigate the use of single-junction InGaAs airbridge cells (ABCs)
at elevated power densities. Such conditions are relevant to many
thermophotovoltaic (TPV) applications, ranging from space to on-demand
renewable electricity, and require effective management of heat and charge
carriers. Experimental characterization of an InGaAs ABC with varying emitter
and cell temperature is used to develop a predictive device model where carrier
lifetimes and series resistances are the sole fitting parameters. The utility
of this model is demonstrated through its use in identifying near-term
opportunities for improving performance at elevated power densities, and for
designing a thermal management strategy that maximizes overall power output.
This model shows that an InGaAs ABC with material quality that leads to the
longest reported carrier lifetimes can attain efficiencies exceeding 40% at 0.5
W/cm2, even when considering the power necessary to cool the cells.
