Display Panel Buffer Layer Reducing OLED–OPD Interface Barriers
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Solution Overview
Problem
The integration of organic photo detectors (OPDs) with organic light emitting diodes (OLEDs) in display panels results in reduced performance due to potential barriers at the interface, affecting the extraction of photoelectrons and lowering the external quantum efficiency (EQE) of the OPD device.
Innovation Solution
Introducing a buffer layer with higher electrical conductivity between the photoelectric conversion layer and the second hole blocking layer, arranged with materials like aluminum and ytterbium, to reduce the interfacial potential barrier and enhance electron transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a photoelectric sensing unit is integrated with a light-emitting unit in a display panel, then the functionality of the display panel is enhanced, but the external quantum efficiency (EQE) of the photo detector is reduced due to potential barriers at the interface
Solution Approach 1:
A buffer layer is introduced between the photoelectric conversion layer and the second hole blocking layer to serve as an intermediary that reduces the potential barrier at the interface. This buffer layer facilitates smoother electron transport from the photoelectric conversion layer to the hole blocking layer, thereby improving the external quantum efficiency of the photo detector while maintaining the integrated structure
Solution Approach 2:
The buffer layer is specifically positioned at the critical interface region between the photoelectric conversion layer and the hole blocking layer. By modifying only this local region with appropriate material properties (higher electrical conductivity), the potential barrier is reduced precisely where it affects electron transport, without altering the overall device structure or other functional layers
2Reliability
If a buffer layer with higher electrical conductivity is introduced between the photoelectric conversion layer and the second hole blocking layer, then the external quantum efficiency is improved, but the device structure becomes more complex
Solution Approach 1:
The interface region between the photoelectric conversion layer and the hole blocking layer is segmented by introducing a separate buffer layer. This segmentation allows independent optimization of the buffer layer's material properties to reduce the potential barrier, while keeping the rest of the device structure unchanged. The buffer layer acts as a distinct functional unit that can be tailored specifically for electron transport enhancement
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 buffer layer significantly improves the external quantum efficiency (EQE) of the OPD by 25% and reduces dark currents, enhancing the overall performance of the photoelectric sensing function.
Implementation Method 1
the buffer layer has a first electrical conductivity, and the second hole blocking layer has a second electrical conductivity, the first electrical conductivity being greater than the second electrical conductivity
Implementation Method 2
the photoelectric sensing unit is configured to receive an optical signal and generate a corresponding electrical signal from the optical signal
Data Source
AI summary
The present application provides a display panel, a display device, and a preparation method for the display panel. The display panel includes: a substrate; a light-emitting unit including a first hole blocking layer; and a photoelectric sensing unit being configured to receive an optical signal and generate a corresponding electrical signal from the optical signal, the photoelectric sensing unit including a photoelectric conversion layer, a buffer layer being arranged on a side of the photoelectric conversion layer away from the substrate and a second hole blocking layer being arranged on a side of the buffer layer away from the photoelectric conversion layer; wherein the first hole blocking layer and the second hole blocking layer are made of the same material, the buffer layer has a first electrical conductivity, and the second hole blocking layer has a second electrical conductivity, the first electrical conductivity being greater than the second electrical conductivity.