Temperature-dependent PL measurements document that the emission intensity of the low energy band decreases with increasing temperature, a hallmark of phosphorescence behavior (Figure ). At 77 K, the tPh is much longer at 553 ms (Figure ). Temperature-dependent phosphorescence spectra show no profile changes other than the phosphorescence intensity (Figure ), confirmed in the timeresolved phosphorescence mapping (Figures and). These studies demonstrate that phosphorescence across all temperature ranges occurs from the same species. To verify that the RTP occurs from a monomolecular species, we recorded the steady-state PL spectra as a function of doping concentration, ranging from 0.1 to 2 wt% TPA-CO2H in PVA (Figure ). A modest red-shift in the onset of the steady-state PL was noted with increasing doping ratio over this range (Figure ). We attribute this to contributions from aggregation-induced excimer fluorescence, evidenced by the unchanged excitation spectra as a function of doping concentration (Figure ). Further, there was no concentration-induced red-shifting of the PL spectra at 77 K (Figure ), which supports the contention that there is aggregation-induced excimer fluorescence at room temperature. Notably, the RTP energy and relative contribution to the steady-state PL are concentration-independent (Figure ). This implies that the RTP occurs only from the monomolecular T1 state. The recorded overall FPL at 298 K in air decreases from 70 to 53% as the doping concentration increases, reflecting an aggregation-caused quenching (ACQ) of the fluorescence.