Effectively enhancing the room temperature phosphorescence (RTP) emission of pure organic phosphors is the goal that scholars continue to pursue. In this study, as a novel strategy, diacetylene monomers were introduced into a pure organic molecule, 2-(9H-carbazol-9-yl) ethanol (CZEO). Upon UV-irradiation, the formed polydiacetylene (PDA) backbones caused a significant enhancement of the RTP emission. RTP emission was continuously enhanced with the time UV-irradiation. In addition, the synergistic enhancement with the help of halogen bonds was realized by introducing Br atoms into the CZEO unit.