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

Abstract

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.

Controlling the Emission Spectrum of Binary Emitting Polymer Hybrids by a Systematic Doping Strategy via Förster Resonance Energy Transfer for White Emission

“…The exponential relationship between Aπ and ΦDA (Figure 14) confirmed that the addition of the MDMO-PPV-DMP or MEH-PPV produces binary hybrids with highly fluorescent. Moreover, an approximately linear portion can be observed when ΦDA exceeded 0.2, with a zero value of Aπ at ΦDA ~0.5, which is consistent with the theoretical results [15,26].…”

“…Moreover, an approximately linear portion can be observed when Φ DA exceeded 0.2, with a zero value of A π at Φ DA ~0.5, which is consistent with the theoretical results [15,26].…”

“…Moreover, Figure 4 shows that the absorption peak wavelength of the donor (~380 nm) was slightly red shifted and its absorbance dramatically decreased upon addition various content of the acceptor (MEH-PPV or MDMO-PPV-DMP) in the binary hybrids, which may lead to tune the conjugation length of the donor [24,25]. Additionally, new absorption peaks centered at 500 and 510 nm in the PFO/MDMO-PPV-DMP and PFO/MEH-PPV binary hybrids, respectively, were enhanced upon increments of the acceptor content, implying the possibility of dimer formation in the binary hybrids [14,26]. The absorption and fluorescence spectra of pristine MEH-PPV and MDMO-PPV-DMP (at concentrations equivalent to the weight ratios used in the binary hybrids) are presented in Figure 5.…”

Tuning the Optical Properties of MEH–PPV/PFO Hybrid Thin Films via the Incorporation of CsPbBr3 Quantum Dots

“…This theory of non-radiative energy transfer was also confirmed by the significant overlap observed between the absorption spectra of PQDs and the fluorescence spectra of the MEH-PPV/PFO conjugated polymers, as shown in Figure 11. The efficient of non-radiative energy transfer (Förster resonant energy transfer) from both PFO and PQDs to MEH-PPV and from PFO to PQDs in the ternary blend were proved in our recent report [45]. In the future, polymer hybrids that possess a smooth surface and can undergo considerable non-radiative energy transfers will play a vital role in the development and optimization of optoelectronic devices.…”

Hybrid of Conjugated Polymers with Incorporation of Metal Oxide Nanocomposites for Improving Optoelectronic Properties

“…This peak is likely due to energy transfer from F8 to both acceptors, which is enhanced by the presence of STNC and possibly dimer formation in the ternary hybrids. [ 35,36 ]…”