There is at least one common material – SiC (it may be unique) which can be fabricated to convert blackbody to quasi monochromatic IR.
There are a number of papers about this, but the first one that pops up is “Extraordinary Coherent Thermal Emission From SiC Due to Coupled Resonant Cavities” Nev, et al From: Eric Walker Stephen A. Lawrence wrote: The idea seems to be that you put a collector made of nanotubes and nanophotonic crystals in front of the cell and it "transforms" the incoming sunlight from a mishmosh of frequencies into a nearly monochromatic beam, whose frequency is centered on the band the cell can convert. This sounds like a blackbody-to-monochromatic light converter. Will physical principles allow such a thing without expenditure of energy? Eric