Photo-physical characterisation and travelling-wave lasing of some TPD-based polymer neat films

Abstract Travelling-wave lasing (amplification of spontaneous emission) is reported for neat films of a series of five red, green and blue emitting TPD-based polymers, the TPD-phenylenevinylene and the TPD-xylylene copolymers. Thin samples on glass substrates were fabricated by spin-coating and transversally pumped with picosecond excitation pulses (wavelength 347.15 nm, duration 35 ps). Lasing occurs around 421, 536, 540, 571, and 618 nm with a line-width smaller than 10 nm. The threshold pump pulse energy densities are determined and found to be 60 μJ / cm 2 for the blue emitting non-conjugated polymer (Poly-TPD(4M)-DPX) and 6–8 μJ / cm 2 for the green and red emitting conjugated polymers TPD(4M)-MEH-PPV and TPD(4M)-MEH-M3EH-PPV. The laser output saturation at high excitation energy densities is studied. The length of effective amplification of spontaneous emission is approximately 1 mm. Effective stimulated emission cross-sections are derived from the pump pulse energy density dependent spectral narrowing of the amplified emission signals. The optical constants (absorption spectrum and refractive index spectrum) of the neat films are determined by reflection and transmission measurements. The absorption cross-section spectra are extracted. The fluorescence quantum efficiencies and the fluorescence lifetimes are measured.

[1]  Alfons Penzkofer,et al.  FLUORESCENCE SPECTROSCOPIC BEHAVIOUR OF NEAT AND BLENDED CONJUGATED POLYMER THIN FILMS , 1999 .

[2]  P. Barbara,et al.  Unmasking electronic energy transfer of conjugated polymers by suppression of O(2) quenching , 2000, Science.

[3]  Alfons Penzkofer,et al.  Optical constants measurement of luminescent polymer films , 1999 .

[4]  S. J. Strickler,et al.  Relationship between Absorption Intensity and Fluorescence Lifetime of Molecules , 1962 .

[5]  Gerwin H. Gelinck,et al.  Narrow-band emissions from conjugated-polymer films , 1997 .

[6]  Hartwig Tillmann,et al.  Amplified spontaneous emission in neat films of arylene-vinylene polymers , 2001 .

[7]  D. Bradley,et al.  Effective stimulated emission and excited-state absorption cross-section spectra of poly(m-phenylenevinylene-co-2,5-dioctoxy-p-phenylenevinylene) and t,t′-didecycloxy-II-distyrylbenzene , 1997 .

[8]  Alan J. Heeger,et al.  Conjugated polymers as solid-state laser materials , 1997 .

[9]  Volker Wittwer,et al.  A flexible conjugated polymer laser , 1998 .

[10]  A. Penzkofer,et al.  Amplified spontaneous emission in rhodamine dyes: Generation of picosecond light pulses and determination of excited state absorption and relaxation , 1978 .

[11]  Hartwig Tillmann,et al.  D. Raabe, H.-H. Hörhold, Travelling-Wave Lasing in Neat Films of Arylene-Vinylene Polymers, , 2000 .

[12]  Alan J. Heeger,et al.  Semiconducting (Conjugated) Polymers as Materials for Solid‐State Lasers , 2000 .

[13]  Mats Andersson,et al.  Semiconducting Polymers: A New Class of Solid-State Laser Materials , 1996, Science.

[14]  A. C. Testa,et al.  2-Aminopyridine as a standard for low-wavelength spectrofluorimetry , 1968 .

[15]  W. Spirkl,et al.  Nonlinear Emission and Recombination in Conjugated Polymer Waveguides , 1999 .

[16]  H. Hörhold,et al.  Photophysical characterization of diphenyl-substituted phenylenevinylene and diphenylenevinylene polymers , 2001 .

[17]  Donal D. C. Bradley,et al.  Spectral narrowing phenomena in the emission from a conjugated polymer , 1998 .

[18]  K. Yoshino,et al.  Lasing and stimulated emission in /spl pi/-conjugated polymers , 2000, IEEE Journal of Quantum Electronics.

[19]  Alfons Penzkofer,et al.  Optical constants measurement of single-layer thin films on transparent substrates , 1998 .

[20]  Alfons Penzkofer,et al.  Energy density dependent fluorescence quenching of diphenyl substituted phenylene-vinylene and diphenylene-vinylene polymers by exciton–exciton annihilation , 2001 .

[21]  Alfons Penzkofer,et al.  Laser performance studies of para-(phenylene-ethynylene) polymers in organic solvents , 1997 .

[22]  R. H. Friend,et al.  Lasing from conjugated-polymer microcavities , 1996, Nature.

[23]  Victor V. Krasnikov,et al.  Blue superradiance from neat semiconducting alternating copolymer films , 1996 .

[24]  J. B. Birks,et al.  The relations between the fluorescence and absorption properties of organic molecules , 1963, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[25]  Alfons Penzkofer,et al.  Photo-physical and lasing characterization of an aromatic diamine-xylylene copolymer , 2000 .

[26]  Wilhelm Elflein,et al.  Synthesis of TPD-containing polymers for use as light-emitting materials in electroluminescent and laser devices , 2001, SPIE Optics + Photonics.

[27]  Daniel Moses,et al.  Semiconducting polymer distributed feedback lasers , 1998 .

[28]  Hartwig Tillmann,et al.  Travelling-wave lasing of triphenylamine-based poly(phenylene vinylene) , 2001 .

[29]  Hartwig Tillmann,et al.  MEH-PPV and dialkoxy phenylene vinylene copolymers. Synthesis and lasing characterization , 2001 .

[30]  Mats Andersson,et al.  A polythiophene microcavity laser , 1998 .

[31]  Ullrich Scherf,et al.  Blue green stimulated emission from a high gain conjugated polymer , 1997 .

[32]  Alan J. Heeger,et al.  Laser emission from solutions and films containing semiconducting polymer and titanium dioxide nanocrystals , 1996 .

[33]  S. J. Jacobs,et al.  Exciton-exciton annihilation in poly (p-phenylenevinylene) films , 1996 .

[34]  A. Penzkofer,et al.  Theoretical investigation of amplified spontaneous emission with picosecond light pulses in dye solutions , 1978 .