Extensive research efforts have continuously been devoted to develop efficient sensitisers absorbing in the visible range, with the most important aspects being the price and/or toxicity of the metal and the lifetime of the relevant MLCT states . An immense achievement was made a decade ago towards replacing photosensitisers based on precious metals, such as Ru and Ir, by Earthabundant Fe complexes. This breakthrough was obtained owing to the utilisation of strongly σ -donating N-heterocyclic carbene (NHC) ligands , which destabilise metal-centered (MC) excited states , that otherwise rapidly, in ca. 100 fs quench the MLCTs in common Fe complexes such as Fe(II) polypyridines . Across the years, numerous Fe-NHC complexes were synthesised and characterised with MLCT lifetimes ranging from 9 ps for the firstdiscovered Fe(II) sensitiser up to 528 ps ; even higher excitedstate lifetimes could be achieved for mixed MLCT-type states, socalled π * to ligand charge transfer (PALCT) for Fe(II) complexes containing amide donor atoms (2.0 -2.7 ns) and for ligand-tometal charge transfer (LMCT) states in an Fe(III)-carbene complex (2 ns) .