Blue green stimulated emission from a high gain conjugated polymer

Zenz, Christian; Graupner, W.; Tasch, S.; Leising, G.; Müllen, Kläus; Scherf, Ullrich

doi:10.1063/1.119332

Cited by 115 publications

(49 citation statements)

References 17 publications

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“…For some other polymers, the ASE wavelength is shifted to larger wavelengths (relative to the peak spontaneous emission wavelength) because absorption near the band edge reduces the net gain. [58] For other polymers, the ASE wavelength is closer to the band edge because excited-state absorption reduces the net gain at larger wavelengths. [49] In general, however, for the best lasing polymers, losses do not affect the gain spectrum too seriously and ASE occurs at the wavelength where spontaneous emission is strongest because the gain is highest there.…”

Section: Amplified Spontaneous Emissionmentioning

confidence: 99%

Semiconducting (Conjugated) Polymers as Materials for Solid-State Lasers

2000

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Light‐emissive polymers are outstanding laser materials because they are intrinsically “4‐level” systems, they have luminescence efficiencies higher than 60 % even in undiluted films, they emit at colors that span the visible spectrum, and they can be processed into optical quality films by spin casting. The important materials issues are reviewed and the prospects for making polymer diode lasers are discussed.

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Section: Amplified Spontaneous Emissionmentioning

confidence: 99%

Semiconducting (Conjugated) Polymers as Materials for Solid-State Lasers

2000

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“…[30] Meanwhile, ASE has been observed in a variety of conjugated polymers. Among these polymers are poly(p-phenylenevinylene)-type materials, [31] fully ladder-type poly(p-phenylene) (MeLPPP) [32] and polyfluorene type polymers. [33] Recently, we demonstrated very low onset threshold values for amplification of blue light (469 nm) in combination with excellent oxidative stability in thin films of poly(ladder-type indenofluorene) P2 in slab waveguide structures.…”

Section: Amplified Spontaneous Emission (Ase)mentioning

confidence: 99%

Photophysical Properties of a Series of Poly(ladder‐type phenylene)s

Laquai

Mishra

Ribas

et al. 2007

Adv Funct Materials

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The photophysical properties, i.e., the fluorescence and phosphorescence of a series of blue light‐emitting poly(ladder‐type phenylene)s have been investigated employing continuous‐wave (cw) and time‐resolved photoluminescence (PL) spectroscopy in solid state and dilute solution. The chemically well‐defined polymers vary from two to five bridged phenyl‐rings per monomer unit bearing aryl‐ or alkyl‐substitution at the bridge‐head carbon atoms. It has been found that the fluorescence energy of the polymers and of the corresponding monomers deviates from a simple 1/N dependence, if the number N of bridged‐phenylene rings is increased beyond a certain limit. Time‐resolved fluorescence spectroscopy on thin films showed that apart from the blue fluorescence of the polymers an additional lower energy emission feature exists, which cannot be assigned to keto‐defects and which seems to be an inherent solid state property of this class of materials. Delayed time‐resolved photoluminescence spectroscopy allowed the detection of phosphorescence energies and lifetimes for all investigated polymers. Photoinduced absorption spectroscopy on thin films showed that the triplet‐triplet absorption red‐shifts with increasing monomer length but reaches a constant value for polymers with N ≥ 4. Amplification of light via amplified spontaneous emission (ASE) from thin film slab waveguide structures could be demonstrated for all ladder‐type polymers but the onset threshold value for ASE varies significantly with the polymer structure.

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“…The methyl-substituted poly͑para-phenylene͒-type ladderpolymer (m-LPPP) is highly attractive for applications in organic light-emitting diodes 1 ͑OLED's͒ and as the active medium in organic solid-state lasers 2 due to its high photoluminescence ͑PL͒ quantum yield PL ϳ30% in film and ϳ100% in solution, 3 and the high interchain order in the solid state. 4,5 From previous studies on m-LPPP a comprehensive picture of the generation of polarons [6][7][8] and triplet excitons 8,9 ͑TE's͒ from singlet excitons ͑SE's͒ was drawn.…”

Section: Introductionmentioning

confidence: 99%

Interaction of singlet excitons with polarons in wide band-gap organic semiconductors: A quantitative study

et al. 2001

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The steady-state photoinduced absorption ͑PA͒, photoluminescence ͑PL͒, PL-detected magnetic resonance ͑PLDMR͒, and PA-detected magnetic resonance ͑PADMR͒ of poly-and oligo-͑para-phenylenes͒ films is described. In particular, the excitation density ͑laser power͒ N 0 dependence of the PA, PL, and PLDMR signals is analyzed by means of a rate equation model, which describes the dynamics of singlet excitons ͑SE's͒ and polarons in all three experiments quantitatively with the same set of parameters. The model is based on the observations that mobile SE's are quenched by trapped and free polarons and that the spin-1 2 magnetic resonance conditions reduce the total polaron population. Since the sublinear N 0 dependences of the positive ͑PL-enhancing͒ spin-1 2 PLDMR and the polaron PA band are essentially the same, we conclude that PLDMR is due to a reduced quenching of SE's by polarons. The agreement between the model, the current results, and results from other spectroscopic techniques provides strong evidence for this quenching mechanism. This also suggests that it is a very significant process in luminescent -conjugated materials and organic light-emitting devices. Consequently, the quenching mechanism needs to be taken into account, especially at high excitation densities, which is of great importance for the development of electrically pumped polymer laser diode structures.

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Blue green stimulated emission from a high gain conjugated polymer

Cited by 115 publications

References 17 publications

Semiconducting (Conjugated) Polymers as Materials for Solid-State Lasers

Semiconducting (Conjugated) Polymers as Materials for Solid-State Lasers

Photophysical Properties of a Series of Poly(ladder‐type phenylene)s

Interaction of singlet excitons with polarons in wide band-gap organic semiconductors: A quantitative study

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