Quantum dot light-emitting diode doped with charge transport layer and preparation method

Abstract

The invention discloses a quantum dot light-emitting diode doped with a charge transport layer. The quantum dot light-emitting diode comprises an anode layer, a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer and a cathode layer which are sequentially arranged from bottom to top, the material of the hole transport layer is a mixture of two hole transport materials; the material of the electron transport layer is a polymer doped electron transport material. Two hole transport materials are mixed to serve as the hole transport layer, the hole injection efficiency is improved, the polymer doped electron transport material serves as the electron transport layer, electron injection is reduced, electron injection is reduced while hole injection is improved, carriers in the quantum dot light-emitting layer are more balanced, and therefore the device performance is improved.

Description

technical field [0001] The invention relates to the technical field of light emitting diodes, in particular to a quantum dot light emitting diode doped with a charge transport layer and a preparation method thereof. Background technique [0002] Quantum dots have attracted extensive attention from academia and industry because of their many advantages such as tunable emission spectra in size and composition, high color saturation, solution processing of quantum dot light-emitting diodes (QLEDs) prepared from them, and low manufacturing costs. QLED has emerged as a competitor to the next generation of high-performance display technology. [0003] The QLED device structure mainly includes an anode, a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a metal cathode. Since the first appearance of QLEDs in 1994, through continuous optimization of quantum dots, charge transport materials, and device structures, the...

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Problems solved by technology

The performance of blue QLEDs is far inferior to that of green and red QLEDs. The deep valence band of blue quantum dots makes hole injection difficult, resulting in unbalanced carrier injection, which increases the possibility of Auger recombination, so the device performance is relatively low. Difference

[0004] In order to reduce the hole injection barrier, currently commonly used deep HOMO energy level hole transport materials such as PVK (HOMO energy level is 5.8eV) have a lower hole mobility of 2.5*106cm 2 v - 1s -1 , so hole injection is still low, commonly used high hole mobility hole transport materials such as TFB (hole mobility 1.0*102cm 2 v -1 the s -1 ) has a shallow HOMO energy level, and has a large transport barrier with quantum dots, resulting in difficulty in hole injection, while the commonly used electron transport material ZnO has a small transport barrier with quantum dots and high electron mobility, which leads to device Medium carrier injection imbalance

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