Charge transport properties of MDMO PPV thin films cast in different solvents

Abstract

Charge transport properties in thin films of Poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene) (MDMO PPV) cast using either chloroform (CF), toluene (TOL), or chlorobenzene (CB) as solvent were investigated. Hole mobility (μ) in these thin films measured using time‐of‐flight transient photoconductivity showed an increasing trend with respect to the solvent used in the same order, that is, μCF (2.4 × 10−7 cm2/Vs) < μTOL (6.9 × 10−7 cm2/Vs) < μCB (2.3 × 10−6 cm2/Vs). Observed variations in mobilities were attributed to different morphologies of MDMO PPV chains in thin films cast using the aforesaid solvents. Nature of the interchain interactions and aggregate formation were obtained using photoluminescence (PL), Raman spectroscopy, and AFM studies. Ratio of PL peak intensities of 0–0 and 0–1 transitions, which is a direct measure of interchain interaction, was the highest in CB and lowest in CF. Variation in the relative intensities of out‐of‐plane wagging of vinylene group (∼963 cm−1 mode) in Raman spectra suggested different extent of coiling of polymer chains in these thin films. From these observations, it was elicited that aggregate size and interchain interactions are highest in CB and least in CF. AFM‐based topographic images of thin films further supported these variations in the size of aggregates. Variation in the aggregate sizes and interchain interactions explained the corresponding variation in the mobility. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1431–1439

Spectral Behavior of a Conjugated Polymer MDMO-PPV Doped with ZnO Nanoparticles: Thin Films

“…The MDMO-PPV thin film PL spectrum shows two emission bands centered at ∼ 575 nm and ∼ 600 nm as illustrated in Figure 5a. These peaks are associated with the 0 − 0 and 0 − 1 vibronic transitions, respectively [52,53]. MDMO-PPV polymer emission occurs through electronic transitions between electronic states in different vibrational states [54].…”

3D-printed flexible organic light-emitting diode displays

“…The electroluminescent polymer MDMO-PPV was selected as the emitter of the 3D-printed OLEDs (Fig. 1C) because of its high performance and stability for both light emitting and photovoltaic applications (37)(38)(39). With the selected material system and successful charge injection enabled by the alignment of energy bands (retrieved from literature) (40)(41)(42)(43), the targeted recombination of charge carriers in the MDMO-PPV layer was achieved.…”