We have seen so far that (i) PTI-samples obtained at low temperature conditions (550 °C, 48 h) show enhanced electrical properties and that (ii) we are able to process PTI-materials from dispersions. In the following, we successfully prepare a prototype OLED with Ca/Al as the cathode, PEDOT:PSS/ITO as anode, and PTI-LiBr as the active material (Figure ). We observe a relatively low luminance of 2 cd m -2 even at high current densities (Figure ), that is most likely caused by film inhomogeneities introduced during drop-casting of the PTI-LiBr layer. Similar to previous observations for CN-films, the electroluminescence maximum of PTI-LiBr is red/shifted by 0.5 eV with respect to the PL maximum (Figure ). Low-energy defect states are a likely explanation for the red-shift. They can arise from small amounts of carbonaceous contaminants still present in the lowtemperature PTI-LiBr sample. The presence of carbonaceous contaminants in the low-temperature PTI-LiBr sample is corroborated in XPS data that shows a contribution in the C-C bond region (Figure ) as well as the still slightly carbon rich CN ratio (Table ).