New Performance Levels for TPV Front Surface Filters

Front surface spectral control filters significantly improve the efficiency of thermophotovoltaic (TPV) converters. Tandem filter designs for 0.52 and 0.60 eV cells were fabricated. Energy and angle weighted spectral efficiencies of ∼83% for the 0.52 eV application and ∼76% for the 0.60 eV applications were achieved with ∼78% angle weighted above bandgap transmission. Manufacturing demonstrations of both designs were completed with good yield. Design improvements were made using angle weighted spectral utilization and above bandgap transmission as refinement goals. Current development work addresses elimination of the plasma filter and alternate substrates.