Polymer Light-Emitting Diode Using a New Electrophosphorescent Cyclometalated Iridium Complex

Abstract

A new iridium-based cyclometalated complex, namely bis (2-phenylpyridine-C 2 , N ) iridium (III) picolinate [(ppy) 2 Ir(pic)] is synthesized and investigated as electrophosphorescent dopant in polymer-based organic light-emitting diodes. The photoluminescence emission from this complex is observed at 501 nm, with a shoulder at 526 nm. Poly(N-vinylcarbazole) (PVK) is used as host polymer and single-layer devices of PVK doped with (ppy) 2 Ir(pic) complex are fabricated. Photoluminescence (PL) spectra of PVK films doped with different concentration of iridium complex were measured to study the possible energy transfer occurring between PVK to iridium complex. A predominant blue to a completely green shifted emission is observed when the doping concentration was increased from 0% to 5 wt%. Optical and atomic force microscopic images of the doped films indicate a smooth film formation when spin coated with chlorobenzene as a solvent as compared to chloroform. Electroluminescence spectra of ITO/PEDOT:PSS/PVK:(ppy) 2 Ir(pic)/Al device resembles that of the PL spectra with emission at 507 nm and Commission Internationale de l'Eclairage (CIE) coordinates (0.29, 0.57).

Electroluminescence and fluorescence emission of poly(n-vinylcarbazole) and poly(n-vinylcarbazole)-Ir(ppy)3-based organic light-emitting devices prepared with different solvents

“…Figure 3 reports the time decays of the fluorescence collected for various emission wavelengths for the two films. 11 A slower decay time and a broader emission spectrum for the PVK CB films, together with a more flat substrate, could already suggest the possibility that the CB prepared film could be more efficient in transferring energy to the dopants. The first is that the lifetimes of the fluorescence signals became systematically longer going from the UV and progressively to the visible range for both the films.…”

Study of Optical and Photovoltaic Properties of N-Alkyl Substituted Polycarbazole Derivative and Its Copolymer with Thiophene

“…Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions INTRODUCTION In recent times, there are broad interests in synthesis of conjugated polymers because of their promising applications in light emitting diodes [1][2][3], field effect transistors [4,5], sensors and actuators [6][7][8], and photovoltaic devices [4,[9][10][11]. Among the various applications of conjugated polymers, exploration of polymer solar cells is of exigent need as it can serve as fossil fuel alternatives.…”