This study has documented the synthesis and characterisation of a family of trimethylsilyl-substituted iridium complexes and their photophysical properties. The addition of the trimethylsilyl groups to the pyridyl ring of the phenylpyridine ligands dampens the vibrational modes that contribute to broadness of the emission spectra, narrowing their emission profile. The complexes with substitution of trimethylsilyl groups at the 4-or 5positions of the pyridine ring showed a modest reduction in the FWHM of 3 to 4 nm, while retaining short emission lifetimes and moderately high FPL. In contrast, substitution at the 4position of the phenyl ring led to a destabilisation of the HOMO and a reordering of the molecular orbitals, resulting in a red-shifting and broadening of the emission spectra as the geometry of the frontier molecular orbitals changed.