Boosting electroluminescence performance of all solution processed In P based quantum dot light emitting diodes using bilayered inorganic hole injection layers

The development of high-performance In P-based quantum dot light-emitting diodes(QLEDs)has become the current trend in ecofriendly display and lighting technology.However,compared with Cd-based QLEDs that have already been devoted to industry,the efficiency and stability of In P-based QLEDs still face great challenges.In this work,colloidal Ni Oxand Mg-doped Ni Oxnanocrystals were used to prepare a bilayered hole injection layer(HIL)to replace the classical polystyrene sulfonate(PEDOT:PSS)HIL to construct high-performance In Pbased QLEDs.Compared with QLEDs with a single HIL of PEDOT:PSS,the bilayered HIL enables the external quantum efficiencies of the QLEDs to increase from 7.6%to 11.2%,and the T_(95)lifetime(time that the device brightness decreases to 95%of its initial value)under a high brightness of 1000 cd m^(-2)to prolong about 7 times.The improved performance of QLEDs is attributed to the bilayered HIL reducing the mismatched potential barrier of hole injection,narrows the potential barrier difference of indium tin oxide(ITO)/hole transport layer interface to promote carrier balance injection,and realizes high-efficiency radiative recombination.The experimental results indicate that the use of bilayered HILs with p-type Ni Oxmight be an efficient method for fabricating high-performance In P-based QLEDs.