Enhanced Optoelectronic Properties of PFO/Fluorol 7GA Hybrid Light Emitting Diodes via Additions of TiO2 Nanoparticles

Abstract

Abstract:The effect of TiO 2 nanoparticle (NP) content on the improvement of poly(9,9 -di-noctylfluorenyl-2,7-diyl) (PFO)/Fluorol 7GA organic light emitting diode (OLED) performance is demonstrated here. The PFO/Fluorol 7GA blend with specific ratios of TiO 2 NPs was prepared via a solution blending method before being spin-coated onto an indium tin oxide (ITO) substrate to act as an emissive layer in OLEDs. A thin aluminum layer as top electrode was deposited onto the emissive layer using the electron beam chamber. Improvement electron injection from the cathode was achieved upon incorporation of TiO 2 NPs into the PFO/Fluorol 7GA blend, thus producing devices with intense luminance and lower turn-on voltage. The ITO/(PFO/Fluorol 7GA/TiO 2 )/Al OLED device exhibited maximum electroluminescence intensity and luminance at 25 wt % of TiO 2 NPs, while maximum luminance efficiency was achieved with 15 wt % TiO 2 NP content. In addition, this work proved that the performance of the devices was strongly affected by the surface morphology, which in turn depended on the TiO 2 NP content.

Long‐range dipole–dipole energy transfer enhancement via addition of SiO2/TiO2 nanocomposite in PFO/MEH‐PPV hybrid thin films

“…The solid state of the donor/acceptor combinations emits light; therefore, such combinations have attracted significant attention as the emissive layer in optoelectronic devices . This enhancement in the emission of the solid state of the donor/acceptor combinations can be attributed to specific aggregation (J‐ or H‐aggregation) or intramolecular planarization in the combinations .…”

“…Unfortunately, the intermolecular interaction occurs in the solid state of donor/acceptor blending, resulting in the quenching of the luminescence . As reported in our previous study, this problem can be diminished by incorporating inorganic nanomaterials …”

“…In our previous studies, the inclusion of TiO 2 NPs prevented the formation of dark quenchers and enhanced the emission performance . Moreover, in a recent study, the visible and ultraviolet emission intensities of SiO 2 /TiO 2 were greater than that of those of pure SiO 2 or TiO 2 NPs .…”

“…Several strategies have been developed to prepare well‐defined inorganic/organic hybrid NCs. The most common of these strategies are via starlike polymer as nanoreactors, sol–gel, in situ polymerization, and solution blending method . In this study, poly (9,9 ′ ‐di‐n‐octylfluorenyl‐2.7‐diyl) (PFO) as a donor and poly [2‐methoxy‐5‐(2‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) as an acceptor were blended at various ratios with and without a SiO 2 /TiO 2 NC by the solution blending method.…”

Applications of Poly(indole-6-carboxylic acid-co-2,2′-bithiophene) Films in High-Contrast Electrochromic Devices

“…Conjugated polymers have sparked enormous attention for applications in solar energy conversion [1,2], electrochromic devices (ECDs) [3][4][5], chemical sensing materials [6,7], catalysts for methanol oxidation in direct methanol fuel cells [8][9][10], and polymer organic light emitting diodes (polymer OLEDs, or PLEDs) [11][12][13] due to their intriguing optical, electrochemical, and structural properties. Among them, the applications of conjugated polymers in developing high contrast electrochromic devices are currently attractive due to their energy-saving and light control properties.…”