Hybrid PVK: OXD-7: QDs Emitting Layer for High Color Purified Quantum Dot Light Emitting-Diode

Abstract

In this paper, we proposed a novel hybrid quantum dot emitting layer (QD EML) for the efficient quantum dot light-emitting diodes (QLEDs). This proposed hybrid emitting layer consisted of a composite polymer with poly (9-vinlycarbazole) (PVK) and 1,3-bis[(4-tert-butylphenyl)-1,3,4oxadiazolyl]phenylene (OXD-7) in the weight ratio of 7:3 and high quantum yield CdSe@ZnS/ZnS quantum dots. By using PVK as hole transport and OXD-7 as electron transport polymer, both hole and electron was supported to inject into QD efficiently. Consequently, the maximum current efficiencies of 7.9 cd/A was achieved in QLEDs with the hybrid EML, which was $\sim 250$ % improvement over the bared EML-device. Moreover, high color purity and wavelength stable green QLEDs with peak wavelength of 536 nm was also obtained.