Fluorescence and phosphorescence behavior of TPD doped and TPD neat films

Photoluminescence spectra of N,N'-bis(3-methylphenyl)-N.N'-bis(phenyl)-benzidine (TPD) are studied in a temperature range from 10 K to room temperature using a neat TPD film, and 5 wt.% TPD doped films with polystyrene (PS), 4,4'-N,N'-dicarbazole-biphenyl (CBP), and polycarbonate (PC) as hosts. The photo-excitation occurred in the singlet absorption region of TPD. The blue fluorescence and green phosphorescence quantum yields, phi(F) and phi(p), of TPD are determined from their quantum distributions. E(F)(lambda) and E(P)(lambda). The yields are found to be phi(F) = 039 and phi(P) = 0.012 for neat films at room temperature, while phi(F) = 0.78 and phi(P) = 0.026 are measured for a TPD doped PS film The lower luminescence quantum yield in the neat film is caused by self-quenching. (C) 2009 Elsevier B.V. All rights reserved.