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

Abstract

In this study, silver-doped nickel oxide (NiO:Ag) 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 NiO:Ag/ ITO substrate at 300 C for 1 h, stable conductive regions and the mean workfunction on the NiO:Ag/ITO surface reached 89.43% and 5.53 eV, respectively, which were greater than those on a conventional poly [3,4-ethylenedioxythiophene] polystyrene sulfonate (PEDOT:PSS)/ITO surface. When NiO:Ag (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/cm 2 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 PEDOT: PSS/ITO anode. Highlights• NiO:Ag is synthesized by a sol-gel method and spin-coated on ITO as a HTL for PLED.• NiO:Ag/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.

Modifying Low-Temperature-Annealed NiOx Nanoparticle Films for Improved Performance of Perovskite Light-Emitting Diodes

“…Figure a,b shows the Ni 2p spectra of the pristine NiO x and PSSNa-modified NiO x films. By fitting the XPS results, it can be seen that Ni 2+ and Ni 3+ components exist in both films, and the signals at 853.9 eV are attributed to the NiO and the 855.6 and 857.5 eV signals correspond to the Ni 2p of Ni 2 O 3 and NiOOH, respectively. − It is found that the PSSNa modification increases the Ni 3+ /Ni 2+ ratio in the NiO x films, with the details given in Table S1. Generally, the Ni 3+ /Ni 2+ ratio can be used as an indicator of the NiO x conductivity, and a higher Ni 3+ /Ni 2+ ratio in the films could contribute to the hole conductivity …”