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

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.