Highly Efficient Double‐Side‐Emitting Electroluminescent Quantum Dot Thin Film with Transparent MoO3/Ag:Cu/MoO3 Electrode Prepared by Thermal Co‐Evaporation

Abstract See‐through double‐side‐emitting electroluminescent quantum‐dot light‐emitting‐diodes (QLEDs) with highly transparent tri‐layer MoO 3 /Ag:Cu/MoO 3 electrode is demonstrated in this study. The tri‐layer MoO 3 /Ag: Cu/MoO 3 electrode is prepared by a thermal co‐evaporation process, in which MoO 3 is utilized as both a seed layer and a capping layer. This tri‐layer structure improves the transmittance as high as ≈88% and ≈86% for pure Ag and Ag:Cu at 550 nm, respectively. It is also found that minor Cu doping significantly improves the thermal stability and sheet resistance of Ag film. With the see‐through tri‐layer film as a device cathode, transparent double‐side‐emitting green QLED exhibits remarkable high brightness of 225, 500 cd m −2 , the current efficiency of 58.68 cd A −1 , the external quantum yield of 16.70%, and transmittance of 77% at 550 nm without any additional anti‐reflection coating.