Study On Synthesis, Optical And Electroluminescent Properties Of Water-/Alcohol-Soluble Conjugated Polymers Based On Poly(Carbazole)s

Organic light-emitting diodes (OLEDs) have drawn considerable interest among researchers and industries because of their great prospective in the field of flat panel display and efficient solid-state lighting. At present, water-/alcohol-soluble conjugated polymers (WSCP) by extensively as electron injection/transport layer material of organic light-emitting diodes(OLEDs) device。Because WSCPs can be processed from solvents, such as methanol and water, in which most conjugated polymers are insoluble. The feature culd solve the problem of mixing between the electroluminescent layer and the adjacent electron-injection layer for the fabrication of multilayer OLED devices by solution processing. It is essential to improve the performance of WSCPs and increase the applications of WSCPs in OLED devices.In this paper, we described the recent research progress of WSCP materials in OLED field. And the new aminoalkyl-substituted cabazole compound(M1) were synthesized. Three WSCPs, including PCCN、PCFN and PCTN, based on the aminoalkyl-substituted cabazole core compound were synthesized by Suzuki coupling reaction. And their quaternized ammonium poly electrolyte derivatives(PCFN-Br and PCTN-Br) were obtained through a postpolymerization treatment on the terminal amino groups.We researched the electron injection properties of polymer PCFN、PCCN、PCTN、PCFN-Br and PCTN-Br, by using PCFN、PCCN or PCTN as electron-injection layer(EIL) in device configuration of ITO/PEDOT:PSS/P-PPV/EIL/A1, the PCCN、PCFN cathode devices’s luminous efficiencies(LE) respectively reached11.1cdA-1and12.1cd A-1, which is more than forty times higher than that of bare Al cathode device. And the PCTN cathode devices’s luminous efficiencies(LE) reached3.02cd A-1, which is more than ten times higher than that of bare Al cathode device. We have showed that such neutral polymers can be used as an electron-injection layer,which can significantly enchance device performance of lighe-emitting plymers with high work-function metals such as Al.The hole injection properties of polymer PCTN-Br were also researched, by using PCTN-Br as hole-injection layer(HIL) in device configuration of ITO/HIL/P-PPV/CsF/Al, the PCTN-Br devices’s LE reached8.28cdA-1, which is more than fifty times higher than that of bare ITO anode device. We have showed that these quaternized ammonium polyelectrolyte derivatives can be used as an hole-injection layer,which can significantly enchance device performance of lighe-emitting plymers.