Organic/Inorganic Hybrid And Inorganic Structure Quantum Dots LEDs

Colloidal quantum dots (QDs) have many outstanding properties, such as high luminescent efficiency, good color purity, wide bandgap tunability and good physical and chemical stability. Colloidal QDs will potentially become foremost materials in next-generation display and lighting.Red, green and blue light QDLEDs have been achieved using the same organic/inorganic hybrid structure by changing different types of QDs (CuInZnS, CdSe and CdZnS/ZnS). In the meantime, for optimal blue QDLEDs’performance the influence of TPD as hole-transporting layer on their characteristics of luminescence has been studied. TPD could improve the balance of charges injection, elevate the luminescence efficiency of QDLEDs, suppress the charging effect of QDs for reducing the recombination of surface states. A model about the process of carriers injection and recombination of charged QDs was proposed to understand the mechanism of QDs surface state emission.In addition, the inorganic blue light QDLEDs were realized using the structure ITO/NiO/QDs/ZnSnO/Ag. NiO can improve the holes injection efficiency, elevate the holes injection, effectively decrease the charging effect of QDs and suppress the recombination of surface states. The utility of inorganic carriers transport layers can bear much higher injected current density, so the QDLEDs can reach stronger luminescence.