The authors have developed a semitransparent, multilayered cathode of indium tin oxide (ITO)/Ag/tungsten oxide (W O3) for transparent organic light-emitting diodes. The device showed a weak negative differential resistance (NDR), until the operating voltage of 8 V was reached. NDR was due to the resonant tunneling by both the quantum barrier and quantum well. The silver oxide (Ag2 O) on the Ag metal was confirmed by x-ray photoelectron spectroscopy, and the energy levels of Ag2 O were quantized due to the quantum size effect and this produced the resonant tunneling channels. The device using ITOAgW O3 with a LiFAl bilayer was superior to those devices which only used ITO or W O3, mainly because the out coupling was enhanced by employing a W O3 material, which is much more transparent than ITO.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)