We present an improved synthetic protocol for PTI-LiBr and highlight the detrimental effects of high synthetic temperatures on the optical and electronic properties of the material. We observe that the hitherto reported synthetic conditions that employ temperatures of 600 °C (and above) give rise to partial carbonisation of PTI-LiBr. The formation of these carbonaceous contaminants in PTI-LiBr give rise to low-energy defect states that deteriorate charge transfer pathways and absorb photoluminescence. We find that protonation of PTI-LiBr happens preferentially at the nitrogen atoms of the triazine (C3N3) moieties. The absorption band of the PTI-backbone is split due to the symmetry breaking upon protonation. Protonation also increased the quantum yield of PTI suspensions up to a factor of 9.This indicates a facile route to partial exfoliation of the π-stacked PTI-structure in solutions of aqueous acids. Finally, we are able to produce an OLED prototype with PTI-LiBr as an active, metal-free material. The maximum of the electroluminescence is red shifted by 0.5 eV in regard to the photoluminescence. This observation is assigned to the presence of trap states. Future use of PTI (and analogous, layered CN-materials) in optical and electronic applications is contingent on (i) further reduction of contributions arising from low-energy defects and (ii) development of methods to access its crystal interfaces as well as PTI monolayers on suited substrates.