Photophysical Properties and Energy Transfer Mechanism in PFO/TiO2/MEH-PPV Nanocomposite Thin Films

A hydrothermal reaction results in the formation of a novel [Pr2(2,5-PA)2(2,5-HPA)2(H2O)4] n·2 nH2O complex (2,5-H2PA = 2,5-pyridinedicarboxylic acid). The complex is structurally characterized by single-crystal X-ray diffraction and crystallizes in the space group P21 of the monoclinic system with two formula units in one cell. This praseodymium complex is characterized by a two-dimensional layered structure. A solid-state photoluminescence experiment reveals that the praseodymium complex shows an emission in the red region. The complex has Commission Internationale de I’Éclairage chromaticity coordinates of 0.5495 and 0.4492. The photoluminescence emission bands could be assigned to the characteristic emission of the 4 f electron intrashell transition of the 3 P0 → 3 H5, 1 D2 → 3 H4, 3 P0 → 3 H6, 3 P0 → 3 F2, and 3 P1 → 3 F3 of the Pr3+ ions. The energy transfer mechanism is explained by the energy level diagrams of the praseodymium ions and the 2,5-H2PA ligand. A solid-state diffuse reflectance measurement shows that the complex possesses a wide optical band gap of 3.48 eV.

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Quantitative cascade energy transfer in semiconductor thin films

Photochemical & Photobiological Sciences ◽

10.1039/c4pp00071d ◽

2014 ◽

Vol 13 (7) ◽

pp. 1031-1038 ◽

Cited By ~ 6

Author(s):

Rebecca Flamini ◽

Assunta Marrocchi ◽

Anna Spalletti

Keyword(s):

Thin Films ◽

Energy Transfer ◽

Charge Transfer ◽

Transfer Mechanism ◽

Energy Transfer Mechanism ◽

Semiconductor Thin Films ◽

Cascade Energy

An energy transfer mechanism, useful to enhance sunlight harvesting, was found to be operative in donor arylacetylenes’ blend thin films, leading to emission only from the bathochromic species, efficiently quenched by charge transfer to [60]PCBM.

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Triplet Energy Transfer Mechanism of Ternary Organic Hybrid Thin Films of PFO/MEH-PPV/CsPbBr3 Perovskite Quantum Dots

Nanomaterials ◽

10.3390/nano10112094 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2094

Author(s):

Bandar Ali Al-Asbahi ◽

Saif M. H. Qaid ◽

Hamid M. Ghaithan ◽

Abdullah S. Aldwayyan

Keyword(s):

Thin Films ◽

Energy Transfer ◽

Transfer Mechanism ◽

Ternary Blend ◽

Energy Transfer Mechanism ◽

Triplet Energy ◽

Blending Method ◽

Donor And Acceptor ◽

Hybrid Thin Films ◽

Triplet Energy Transfer

The triplet energy transfer mechanism of novel poly(9,9-di-n-octylflourenyl-2,7-diyl) (PFO)/poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV)/CsPbBr3 perovskite quantum dot (PQD) hybrid thin films was comprehensively investigated. The concentrations of PFO and MEH-PPV in all the specimens were fixed, while the PQD content was varied with various weight ratios and premixed by a solution blending method before it was spin-coated onto glass substrates. The triplet non-radiative Förster resonance energy transfers (FRETs) in the PFO/MEH-PPV/PQDs ternary blend, the dual FRET from PFO to both PQDs and MEH-PPV, and the secondary FRET from PQDs to MEH-PPV were observed. The values of the Förster radius (Ro) of FRET from PFO to MEH-PPV in the presence of various PQD contents (Case I) increased from 92.3 to 104.7 Å, and they decreased gradually from 68.0 to 39.5 Å for FRET from PFO to PQDs in the presence of MEH-PPV (Case II). These Ro values in both cases confirmed the dominance of FRET in ternary hybrid thin films. Upon increasing the PQD content, the distance between the donor and acceptor molecules (RDA) and the conjugation length (Aπ) in both cases gradually decreased. The small values of Ro, RDA, and Aπ with a decrease in the energy transfer lifetime (τET) due to an increase in the PQD contents in both Cases I and II confirmed the efficient FRET in the hybrid. To prevent intermolecular transfer in PFO, the concentrations of MEH-PPV (Case I) and PQDs (Case II) should be decreased to a range of 0.57–0.39 mM and increased in the range of 1.42–7.25 mM.

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