Ultrafast study of inter‐ and intrachain energy transfer in a core–polymer

Abstract

Interchain interactions can play a positive role in reaching amplified spontaneous emission in an interesting core-polymer system where the donor (side chains) and the acceptor (core) are chemically linked together. Different degree of interchain interactions modifies the photophysical characteristics of the polymer. By means of transient absorption spectroscopy we show that the stimulated emission from the core decreases passing from solid state to concentrated solution and it is almost absent in the diluted solution. The conformational rearrangements of the core-polymer chain in solution limits the efficiency of the intrachain F€ orster energy transfer mechanism. The free chain rotations decrease the exciton hopping along the conjugated chains, the ratio between donor and acceptor moieties in the polymer, and change the relative orientation of the transition dipoles of the donor and acceptor causing a strong decrease of energy transfer efficiency and subsequently of the gain. V C 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 965-969

Deep Blue Light Amplification from a Novel Triphenylamine Functionalized Fluorene Thin Film

“…A losses value of 4.3 ± 0.1 cm −1 has been determined from the best fit of the experimental data. This result allows us to estimate the absolute g (450 nm) value of around 45 cm −1 [32,[46][47][48][49]. In order to correctly compare our results with those obtained from other similar molecules it is important to observe that the ASE threshold strongly depends on the pump pulse time length and also on the phenyl rings number [11,47] in the main backbone.…”

“…The bulky and propeller-shaped TPA structure incorporated into the polymer backbone tends to be packing-disruptive, most of the TPA substituted materials are amorphous, with high thermal stability, good film-forming ability, and good solubility [29][30][31]. Moreover, the propeller like structure of TPA is responsible for a reduced interchain ET to residual fluorenone defects process normally more efficient than the intrachain one [32]. In this way, the color stability of the material is increased.…”

“…In this way, the color stability of the material is increased. The introduction of TPA in OLED active materials has been extensively studied both as a unit in the conjugated backbone [32,33] and as a lateral substituent [34], leading in all cases to considerable improvements in the material [35][36][37][38] performances. Regarding materials for light amplification, the effect of TPA moiety has been instead evaluated only as terminal unit of the main backbone [39] and not yet as lateral substituent.…”

Photoinduced Energy Transfer in Linear Guest–Host Chromophores: A Computational Study

“…Nowadays, prototype devices can meet realistic specifications for applications. , Besides this, their manufacturing processes are simple and inexpensive, involving solution processing , and polymeric film formation . Within these materials, interchain and intrachain energy-transfer processes coexist and parallel their efficiencies to ultimately lead to an effective energy migration − …”