Effect of top metallic contacts on energy conversion performances for near-field thermophotovoltaics
Phys. Rev. Applied 24, 034032 – Published 12 September, 2025
DOI: https://doi.org/10.1103/sxyl-4f3g
Abstract
The design of metallic contact grids on the front side of thermophotovoltaic cells is critical because it can cause significant optical and electrical resistive losses, particularly in the near field. However, from the theoretical point of view, this effect has been either discarded or studied by means of extremely simplified models such as the shadowing methods, that consist of simply ignoring the fraction of the semiconductor surface covered by metal. Our study, based on a rigorous three-body theoretical framework and implemented using the scattering matrix approach with the Fourier modal method augmented with adaptive spatial resolution, provides deeper insight into the influence of the front metal contact grid. This approach allows direct access to the radiative power absorbed by the semiconductor, enabling the proposal of an alternative definition for the thermophotovoltaic cell efficiency. By modeling this grid as a metallic grating, we demonstrate its significant effect on the net radiative power absorbed by the cell and, consequently, on the generated electrical power. Our analysis reveals behaviors differing substantially from those predicted by previous simplistic approaches.
