Dual Mode OLED Cathode Work Function Optimization
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Solution Overview
Problem
Conventional dual mode organic light emitting devices require high driving voltage in reflective mode, leading to high power consumption and reduced lifespan.
Innovation Solution
A dual mode organic light emitting device with a cathode composed of a first metal (Ag, Al, or Cu) and a second metal with a work function of 4.0 eV or less, at a weight ratio of 1:1 to 1:100, along with an electron transport layer and emission layer, reduces driving voltage while maintaining normal and reflective mode operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional dual mode organic light emitting device is used, then it can operate in both normal mode and reflective mode, but it requires high driving voltage in reflective mode leading to high power consumption and reduced lifespan
Solution Approach 1:
The patent changes the material composition parameter of the cathode by using a low work function material (work function of 4.0 eV or less) instead of conventional cathode materials. This parameter change enables the device to operate in reflective mode with reduced driving voltage, thereby lowering power consumption while maintaining dual mode operation capability
Solution Approach 2:
The patent employs a composite cathode structure comprising a low work function material layer combined with other materials. This composite approach allows the device to achieve both normal mode and reflective mode operations with improved voltage characteristics, resolving the contradiction between versatility and energy consumption
2Adaptability or versatility
If a conventional dual mode organic light emitting device is used, then it can operate in both normal mode and reflective mode, but it requires high driving voltage in reflective mode which adversely affects device lifespan
Solution Approach 1:
By changing the work function parameter of the cathode material to 4.0 eV or less, the patent reduces the driving voltage required for reflective mode operation. This parameter modification decreases electrical stress on the device components, thereby extending device lifespan while preserving dual mode operation capability
Solution Approach 2:
The patent uses a low work function material that enables reflective mode operation with lower voltage, effectively creating a more durable operating mode. This material choice allows the device to sustain longer operational duration by reducing voltage-induced degradation
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 solution decreases driving voltage in reflective mode, thereby reducing power consumption and extending the device's lifespan.
Implementation Method 1
the cathode includes a first metal selected from silver (Ag), aluminum (Al), copper (Cu), and gold (Au) and a second metal having a work function of about 4.0 eV or less
Implementation Method 2
an organic light emitting diode (OLED) includes an anode, a cathode, and an organic emission layer that is disposed between the anode and the cathode and emits light as a result of the re-combination of electrons and holes
Data Source
AI summary
A dual mode organic light emitting device and a pixel circuit including the same are disclosed. The dual mode organic light emitting device includes a cathode formed over a substrate, an electron transport layer (ETL) formed over the cathode, an emission layer formed over the electron transport layer (ETL), and an anode formed over the emission layer, wherein the cathode includes a first metal selected from silver (Ag), aluminum (Al), copper (Cu), and gold (Au) and a second metal having a work function of about 4.0 eV or less, and the first metal and the second metal are present at a weight ratio of about 1:1 to about 1:100.