OLED Electron Blocking Layer Doping for Lifetime Extension
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Solution Overview
Problem
The shortening of OLED display panel lifetime due to material instability and device structure design, particularly the recombination of electrons and holes at the interface of the electron blocking layer and light-emitting layer, leading to distortion and bond fracture, which reduces the device's longevity.
Innovation Solution
Doping a hole-type non-metallic material in the electron blocking layer to increase the LUMO energy level, creating a barrier that limits electron transmission and enhances recombination efficiency within the light-emitting layer, thereby prolonging the device's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrons and holes recombine at the interface of the electron blocking layer and light-emitting layer, then light emission is achieved, but material distortion and bond fracture occur, reducing device lifetime
Solution Approach 1:
The patent introduces a hole-type non-metallic material as an intermediary substance doped into the electron blocking layer. This intermediary modifies the energy level structure by increasing the LUMO energy level, creating an energy barrier that mediates the interaction between electrons and the electron blocking layer, thereby preventing direct harmful recombination at the interface while maintaining light emission functionality.
Solution Approach 2:
The patent changes the energy level parameter of the electron blocking layer by doping it with hole-type non-metallic material. Specifically, the LUMO energy level is increased to create a larger energy offset with the light-emitting layer, which alters the electron transmission characteristics and prevents electron accumulation at the interface, thus eliminating the harmful recombination effect.
2Reliability
If the LUMO energy level of the electron blocking layer is increased to prevent electron transmission, then electron accumulation is reduced and device lifetime is extended, but the energy barrier may inhibit necessary electron transport
Solution Approach 1:
The patent applies local quality modification by doping only the electron blocking layer with hole-type non-metallic material, while keeping other layers unchanged. This localized modification creates a specific energy barrier at the electron blocking layer/light-emitting layer interface, which selectively affects electron transmission at this critical location without disrupting electron transport in other regions of the device.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The doping of hole-type non-metallic materials in the electron blocking layer increases the recombination probability of electrons and holes in the light-emitting layer, reducing electron accumulation and minimizing damage to the electron blocking layer, thus extending the OLED device's lifetime.
Implementation Method 1
a surface of the first electron blocking layer in contact with the light-emitting layer is doped with a hole-type non-metallic material
Implementation Method 2
the holes and the electrons are recombined to form excitons. Under the action of the electric field, the excitons migrate and transfer the energy to the light-emitting material, and excite the electrons to transition from a ground state to an excited state. The energy in the excited state generates photons by radiation inactivation to release light energy.
Data Source
AI summary
An organic electroluminescent diode, a display panel, a display device and a manufacturing method of an organic electroluminescent diode are provided. The organic electroluminescent diode includes a first electrode, a first electron blocking layer, a light-emitting layer and a second electrode which are stacked arranged in sequence, a surface of the first electron blocking layer in contact with the light-emitting layer is doped with a hole-type non-metallic material. In the embodiment of the present disclosure, by doping the hole-type non-metallic material in the first electron blocking layer, the density of the holes at the recombination interface is increased, the utilization rate of the holes is improved, and the loss of holes in the transmission process is avoided, which ensures that the holes are timely recombined with the transmitted electrons, and avoids the accumulation of too many electrons at the interface between the first electron blocking layer and the light-emitting layer.