Photophysical and lasing characterization of neat films of 4-methyl-TPD and of a 4-methyl-TPD phenyl substituted MEH-PPV copolymer

Abstract

Wave-guided travelling-wave lasing (amplification of spontaneous emission in waveguide) is studied on neat films of the triphenylamine dimer 4-methyl-TPD, and of the 4-methyl-TPD phenyl substituted MEH-PPV copolymer TPD(4M)-MEH-P-PPV. Laser action is achieved by transverse pumping neat films on glass substrates with picosecond excitation pulses (wavelength 347.15 nm, duration 35 ps). Lasing occurs at 422 nm for 4-methyl-TPD and at 544 nm for TPD(4M)-MEH-P-PPV. The optical constants (absorption spectra and refractive index spectra), the absorption cross-section spectra, fluorescence quantum distributions, fluorescence quantum yields, and fluorescence lifetimes of the samples are determined for photo-physical characterization. The laser performance and the photo-physical parameters of 4-methyl-TPD and TPD(4M)-MEH-P-PPV are compared with results on MEH-PPV.