多功能配体修饰实现高性能蓝光量子点发光二极管OA

Quantum dot(QD)light-emitting diodes(QLEDs)are regarded as promising candidates for next-generation display and lighting technologies due to their excellent optoelectronic properties.However,the performance of blue QLEDs still lags far behind green and red counterparts,which seriously hinders the commercialization of QLED full-color displays.The main challenges arise from the deep valence band energy level of blue QDs,which leads to a large hole injection barrier at the QD/hole-transport layer(HTL)interface,as well as the insulating nature of long-chain oleic acid ligands that hinder charge transport.Moreover,the small energy offset between the core and shell materials in blue QDs facilitates carrier trapping at surface defect states,resulting in non-radiative recombination and thus reducing device efficiency.In this work,we introduce a multifunctional ligand,benzylhydroxylamine hydrochloride(BHACl),to modify the surface of blue QDs.The BHACl molecules replace the native long-chain oleic acid ligands,significantly improving the carrier transport within QD films.Meanwhile,the NH+3 groups effectively passivate surface sulfur dangling bonds,suppressing non-radiative recombination.In addition,the large dipole moment of BHACl upshifts the QD energy levels,thereby reducing the hole injection barrier.Benefiting from these synergistic effects,the fabricated blue QLEDs exhibit an external quantum efficiency(EQE)of 19.2%,a peak luminance of 8 986 cd·m-2,and an operational lifetime of 18 170 h at an initial luminance of 100 cd·m-2,representing substantial improvements over the control devices.