Steady-state and time-resolved studies of 2,7-carbazole-based conjugated polymers in solution and as thin films: determination of their solid state fluorescence quantum efficiencies

2003 ◽  
Vol 370 (5-6) ◽  
pp. 799-804 ◽  
Author(s):  
Soujanya Tirapattur ◽  
Michel Belletête ◽  
Nicolas Drolet ◽  
Mario Leclerc ◽  
Gilles Durocher
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Solid State ◽  
Conjugated Polymers ◽  
Time Resolved ◽  
Solid State Fluorescence

Determination of growth regimes of Pd nanostructures on c-plane sapphire by the control of deposition amount at different annealing temperatures

2017 ◽  
Vol 19 (23) ◽  
pp. 15084-15097 ◽  
Author(s):  
Sundar Kunwar ◽  
Mao Sui ◽  
Puran Pandey ◽  
Quanzhen Zhang ◽  
Ming-Yu Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Solid State ◽  
Structural Evolution ◽  
Pd Nanoparticles ◽  
Annealing Temperatures ◽  
Deposition Amount ◽  
Sputter Deposited ◽  
Different Thickness

Semi-spherical and irregular Pd nanoparticles and voids are fabricated on sapphire(0001) by the solid-state dewetting of sputter-deposited Pd thin films at different thickness and temperature. The structural evolution, surface morphology transformation and optical properties of Pd nanostructures are probed.

scholarly journals Donor–acceptor stacking arrangements in bulk and thin-film high-mobility conjugated polymers characterized using molecular modelling and MAS and surface-enhanced solid-state NMR spectroscopy

2017 ◽  
Vol 8 (4) ◽  
pp. 3126-3136 ◽  
Author(s):  
Sachin R. Chaudhari ◽  
John M. Griffin ◽  
Katharina Broch ◽  
Anne Lesage ◽  
Vincent Lemaur ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Conjugated Polymers ◽  
Molecular Modelling ◽  
Solid State Nmr ◽  
High Mobility ◽  
Surface Enhanced ◽  
Donor Acceptor

DPP-DTT adopts a donor-on-acceptor stacking arrangement which is preserved in thin films.

scholarly journals Mono-, Di-, Tri-Pyrene Substituted Cyclic Triimidazole: A Family of Highly Emissive and RTP Chromophores

Photochem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 477-487
Author(s):  
Daniele Malpicci ◽  
Clelia Giannini ◽  
Elena Lucenti ◽  
Alessandra Forni ◽  
Daniele Marinotto ◽  
...  
Keyword(s):  
Steady State ◽  
Solid State ◽  
Intermolecular Interactions ◽  
Quantum Yields ◽  
Time Resolved ◽  
Tddft Calculations ◽  
Pyrene Molecule ◽  
The Family ◽  
Strong Motivation

The search of new organic emitters is receiving a strong motivation by the development of ORTP materials. In the present study we report on the preparation, optical and photophysical characterization, by both steady state and time resolved techniques, of two pyrene-functionalized cyclic triimidazole derivatives. Together with the already reported mono-substituted derivative, the di- and tri-substituted members of the family have revealed as intriguing emitters characterized by impressive quantum yields in solution and RTP properties in the solid state. In particular, phosphorescence lifetimes increase from 5.19 to 20.54 and 40.62 ms for mono-, di- and trisubstituted compounds, respectively. Based on spectroscopical results and theoretical DFT/TDDFT calculations on the di-pyrene molecule, differences in photophysical performances of the three compounds have been assigned to intermolecular interactions increasing with the number of pyrene moieties appended to the cyclic triimidazole scaffold.

scholarly journals Identification of a Bridge-specific Intramolecular Exciton Dissociation Pathway in Donor-π-acceptor Alternating Conjugated Polymers 

2020 ◽  
Author(s):  
Zhaoyong Jiao ◽  
Tingting Jiang ◽  
Zhongpo Zhou ◽  
Chaochao Qin ◽  
Jinyou Long ◽  
...  
Keyword(s):  
Steady State ◽  
Conjugated Polymers ◽  
Organic Solar Cells ◽  
Transient Absorption ◽  
Dissociation Pathway ◽  
Relaxation Dynamics ◽  
Exciton Dissociation ◽  
Time Resolved ◽  
High Efficient ◽  
Conversion Efficiencies

Abstract Intramolecular exciton dissociation is critical for high efficient mobile charge carrier generations in organic solar cells. Yet despite much attention, the effects of π bridges on exciton dissociation dynamics in Donor-π-Acceptor (D-π-A) alternating conjugated polymers remain still unclear. Here, using a combination of femtosecond time-resolved transient absorption (TA) spectroscopy and steady-state spectroscopy, we track ultrafast intramolecular exciton relaxation dynamics in three D-π-A alternating conjugated polymers which were synthesized by Qin's group and named HSD-A, HSD-B, HSD-C. It is found that the addition of thiophene unit as π bridges will lead to the red shift of steady-state absorption spectrum. Importantly, we reveal the existence of a new intramolecular exciton dissociation pathway mediated by a bridge-specific charge transfer (CT') state with the TA fingerprint peak at 1200 nm in π-bridged HSD-B and HSD-C. This CT' state results in higher electron capture rates for HSD-B and HSD-C as compared to HSD-A. Depending on the proportion of CT' state and nongeminate recombination are important step for the understanding of high power conversion efficiencies in HSD-B than in HSD-C. We propose that this bridge-specific exciton dissociation pathway plays an important role in ultrafast intramolecular exciton dissociation of organic photovoltaic material D-π-A alternating conjugated polymers.

Mixed-Carbene Cyclometalated Iridium Complexes with Saturated Blue Luminescence

2019 ◽  
Author(s):  
Hanah Na ◽  
Louise Cañada ◽  
Thomas Teets
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Methyl Methacrylate ◽  
Nucleophilic Addition ◽  
Blue Luminescence ◽  
Iridium Complexes ◽  
Photoluminescence Properties ◽  
Time Resolved ◽  
Main Text ◽  
Time Resolved Photoluminescence

This work describes the synthesis and photoluminescence of new heteroleptic mixed-carbene cyclometalated iridium complexes. Complexes are synthesized via a nucleophilic addition cascade reaction with isocyanide-bound precursors. The steady-state and time-resolved photoluminescence properties of the compounds are measured, both in solution and in poly(methyl methacrylate) (PMMA) thin films. Full experimental details are given in the main text and supporting information.<br>

Guest Aggregation within Poly(L-lactic Acid)/Pluronic P104 Thin Films

2008 ◽  
Vol 62 (3) ◽  
pp. 290-294 ◽  
Author(s):  
Jordan M. Steves ◽  
Loraine T. Tan ◽  
Joseph A. Gardella ◽  
Robert Hard ◽  
Wesley L. Hicks ◽  
...  
Keyword(s):  
Thin Films ◽  
Lactic Acid ◽  
Steady State ◽  
Fluorescence Spectroscopy ◽  
Biodegradable Polymer ◽  
Rhodamine 6G ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Microscope Slides ◽  
Glass Microscope

Rhodamine 6G (R6G) doped thin films composed of poly(L-lactic acid) (PLLA) and Pluronic P104 were spin cast onto glass microscope slides and characterized by ultraviolet–visible, steady-state, and time-resolved fluorescence spectroscopy. The results show that R6G aggregation within the film increases as the R6G concentration and P104 loading increases. These results suggest an approach for studying drug distributions (monomers, aggregates) within biodegradable polymer formulations.

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