The photophysical properties of Pt(II)-based triplet emitters can be controlled by tuning the Pt(II)...Pt(II) distance. Herein we show that the functionalization and characterization of insulating and semiconducting substrates with triplet emitters can be achieved by a convenient wet-chemical grafting of a pyridine-terminated silane linker on amorphous quartz and on silicon carbide single crystal surfaces. Coordination of the monodentate pyridine unit with phosphorescent Pt(II) complexes bearing tridentate lumino-phores forces the triplet emitters to aggregate by surface constraints, even if bulky substituents such as adamantyl moieties are present. We found that X-ray photoemission spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR FT-IR) constitute adequate tools to ascertain the degree of functionalization; in particular, high resolution XPS spectra revealed the electronic states at the surfaces, which were correlated with the frontier orbitals of the tridentate luminophores and the degree of aggregation of the complexes. Moreover, photoluminescence spectroscopy allowed us to assess the full extension of aggregation caused by the 2D-confinement, whereas fluorescence microscopy was used to evaluate the homogeneity of the phosphorescent layer.