Solution-processed light-emitting diodes consisting of metal-oxide and organic–inorganic hybrid emissive thin films

Abstract

We prepared organic–inorganic hybrid emissive thin films using a simple sol-gel method containing an emissive polymer for improving the operating lifetime of organic materials. The hybrid films can be developed using a precursor solution of tetraethoxysilane (TEOS) and an emissive polymer. In the films, the emissive polymer is encapsulated in SiO2 and not exposed to the atmosphere, thus improving the photoluminescence lifetime of the hybrid films with this sealing effect. We also prepared vanadium pentoxide (V2O5) thin films using a vanadium(V) oxytriisopropoxide (VTIP) precursor solution for application to hole-injection layers in light-emitting diodes (LEDs). The fabricated LEDs consisting of a solution-processed bilayer (hybrid and V2O5) showed improved operating lifetime. These results clearly demonstrate that a good sealing effect on the emissive polymer can be realized in hybrid films using a simple sol-gel method and that V2O5’s hygroscopicity and strong acidity are better than those of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS).