The effect of interface roughness on spectral efficiency of thermophotovoltaics with multi-layer filters

Spectral efficiency is an important parameter to characterize the optical performance of optical filters in thermophotovoltaic systems. The multilayer filters are normally designed by assuming ideally flat interfaces, but realistic structures have a degree of interface roughness present. This work explores the influence of interface roughness on the spectral efficiency, with examples including structures with different materials or number of layers.