Inverted quantum-dot light emitting diodes with cesium carbonate doped aluminium-zinc-oxide as the cathode buffer layer for high brightness

Abstract

We report an inverted structure of quantum-dot light emitting diodes (QLEDs) with cesium carbonate (Cs₂CO₃) doped aluminum-zinc-oxide (AZO) as the cathode buffer. The Cs₂CO₃ doped AZO with Cs₂CO₃ blending ratios (AZO : Cs₂CO₃) from 4 : 1 to 2 : 1 was used as an electron transport layer in QLEDs. It is found that the conductivity of the AZO : Cs₂CO₃ blended solution increases with the increase in the concentration of Cs₂CO₃ until a particular concentration, and the luminance intensity increases sharply from 9949 to 57 350 cd m⁻². It is concluded therefore that Cs₂CO₃ doped AZO could be a good cathode buffer for inverted QLEDs.