Enhanced polymer light-emitting diode property using fluorescent conducting polymer-reduced graphene oxide nanocomposite as active emissive layer

Abstract

The present article reports the polymer light-emitting diode property of the nanocomposite comprising poly 9,9-dioctyl fluorene-alt-bithiophene and reduced graphene oxide used as an emissive layer. Two times repetition of Hummers oxidation and hydrazine hydrate reduction method produce reduced graphene oxide (term as rGO2) with more uniform distribution in size and thickness. In addition, this uniquely synthesized rGO2 induces favorable shift in balance of electron and hole recombination zone toward the center of emissive layer owing to increase in in-plane crystallite size and high localize aromatic confinement. Five times increase in maximum device efficiency (Cd/A) and three times increase in maximum brightness (Cd/m 2 ) are achieved with the LED device using nanocomposite as emissive layer compared to neat polymer. Also, the fabricated device requires relatively low turn-on voltage (4 V) because of low energy barrier between PEDOT work function (-5.0 eV) and HOMO levels of bi-thiophene copolymer -5.67 eV) and nanocomposite (-5.66 eV).

Graphene-Polymer based Nanocomposites for Electrochemical Sensing of Toxic Chemicals

“…Figure 2 shows multifunction applications of graphene-polymer based nanocomposites. Some conjugated polymer functionalized graphene like polythiophenes or its derivative composites are widely used in photovoltaic devices [30], light-emitting diodes [31,32], transparent conducting electrodes [33], gas barrier membranes [34,35], and biosensors [36][37][38]. Meanwhile, conducting polymers such as polyaniline and polypyrrole functionalized graphene composites show a great potential application in supercapacitors [39,40] and lithium-ion battery electrode [41].…”

Effect of partially reduced fullerenol‐graphene hybrid nanofiller on photophysical and super capacitance properties of fluorescence conducting polymer nanocomposites

“…It is pertaining to mention here that the uniform dispersion of nanoparticles into the conducting polymers matrix is an essential requirement to produce synergistic effect in the properties of “hybrid conducting nanocomposites.” Significant enhancements in energy storage properties are thus observed during their device applications. [ 17,18 ] In addition, enhanced mechanical property and improved electrical conductivity are observed in many cases owing to synergetic effect produced by homogeneous dispersion of carbon nanostructured materials (i.e., fullerene, CNT, graphene, etc.) into conducting polymer matrices.…”

Computational Studies on the Materials Combining Graphene Quantum Dots and Pt Complexes with Adjustable Luminescence Characteristics

“…17 But it is not a perfect idea to dope graphene into the emissive layer according to Singh et al's work. 18 This strategy allows electron and hole recombining at the interior of the emitting functional layer more possibly and enhances luminescence and efficiency, but the presence of graphene may cause PL quenching due to electronic interactions. Is there a better way to combine the advantages of graphene and OLED in the emissive layer?…”

“…A hole-transport layer doped with graphene, as studied by Posudievsky et al, showed better performance in terms of current density, brightness, and luminous efficiency based on the improved carrier transportation . But it is not a perfect idea to dope graphene into the emissive layer according to Singh et al’s work . This strategy allows electron and hole recombining at the interior of the emitting functional layer more possibly and enhances luminescence and efficiency, but the presence of graphene may cause PL quenching due to electronic interactions.…”