We report highly efficient quantum dot light-emitting diodes (QLEDs) with TiO2 nanoparticles (NPs) as an alternative electron transport layer (ETL) and poly (methyl methacrylate) (PMMA) as an insulating layer. TiO2 NPs were applied as ETLs of inverted structured QLEDs and the effect of the addition of PMMA between ETL and emission layer (EML) on device characteristics was studied in detail. A thin PMMA layer supported to make the charge balance in the EML of QLEDs due to its insulating property, which limits electron injection effectively. Green QLEDs with a PMMA layer produced the maximum luminance of 112,488 cd/㎡ and a current efficiency of 25.92 cd/A. We expect the extended application of TiO2 NPs as the electron transport layer in inverted structured QLEDs device in the near future.
