Silver-doped nickel oxide as an efficient hole-transport layer in polymer light-emitting diodes.

ABSTRACT

In this study, silver-doped nickel oxide (NiOAg) was successfully synthesized by a sol-gel method and spin-coated on indium titanium oxide (ITO) as a hole-transport layer for polymer light-emitting diodes (PLED). After the calcination of the NiOAg/ITO substrate at 300°C for 1 h, stable conductive regions and the mean work-function on the NiOAg/ITO surface reached 89.43% and 5.53 eV, respectively, which were greater than those on a conventional poly [3,4-ethylenedioxythiophene] polystyrene sulfonate (PEDOTPSS)/ITO surface. When NiOAg (300°C)/ITO was used as an anode window substrate for PLEDs, the enhancement factor for the average current efficiency in the current-density range of 20-50 mA/cm2 and electroluminescence intensity at an applied bias of 8.0 V were 4.60 and 2.55 times, respectively, in comparison with those of PLED based on a conventional PEDOTPSS/ITO anode. HIGHLIGHTS NiOAg is synthesized by a sol-gel method and spin-coated on ITO as a HTL for PLED. NiOAg/ITO calcined at 300°C for 1 h has the best microscopic electrical properties. The performance for proposed PLED is much better than that for typical PLED.