Tandem OLED Microcavity Blue Light Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Active matrix organic light-emitting diode (AMOLED) display panels face issues with low efficiency and short service time for blue light emission, which limits the development of AMOLED products.
Innovation Solution
A tandem bottom-emitting OLED structure is developed, featuring a substrate with a thin-film transistor layer, transparent first electrode, charge generation layer with a reflective portion, and multiple light-emitting layers to enhance blue light emission, including a microcavity structure that converts green and red light into blue light, improving intensity and service time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the area of blue pixels is increased to extend service time, then the service time is extended, but the overall device complexity and structure become more complex
Solution Approach 1:
The patent implements a nested structure where the first light-emitting layer (emitting green/yellow light) is positioned above the second light-emitting layer (emitting blue light), with the charge generation layer nested between them. The microcavity structure further nests reflective portions within the charge generation layer to redirect and convert light. This nested arrangement allows multiple functional layers to be integrated vertically, extending blue light service time through optical conversion without increasing lateral device footprint or structural complexity.
Solution Approach 2:
The patent transitions from a lateral expansion approach to a vertical stacking approach by introducing multiple light-emitting layers arranged in the vertical dimension. The first light-emitting layer emits green/yellow light that is redirected downward by the microcavity structure into the second light-emitting layer, which converts it to blue light. This vertical arrangement solves the service time issue without requiring increased pixel area or lateral structural complexity.
2Device complexity
If conventional blue light-emitting materials are used, then the structure is simple, but the emission efficiency is low and service time is short
Solution Approach 1:
The patent introduces the first light-emitting layer as an intermediary that emits green/yellow light, which then serves as the input for the second light-emitting layer to generate blue light. The charge generation layer acts as another intermediary, facilitating charge transfer between the two light-emitting layers and enabling the optical conversion process. This intermediary approach achieves high emission efficiency and extended service time through coordinated interaction between multiple layers rather than relying on a single conventional blue light-emitting material.
Solution Approach 2:
The patent changes the emission wavelength parameter by using the first light-emitting layer to emit green/yellow light (longer wavelength) that is then converted to blue light (shorter wavelength) by the second light-emitting layer. This parameter transformation, achieved through optical conversion in the microcavity structure, enables high emission efficiency and extended service time by utilizing the stability of green/yellow light-emitting materials while producing the desired blue light output.
3Illumination intensity
If blue light intensity is increased to improve display performance, then the brightness is improved, but the service time decreases
Solution Approach 1:
The patent converts the inherent limitation of blue light-emitting materials (short service time) into a benefit by using green/yellow light-emitting materials with long service times in the first light-emitting layer. These materials emit green/yellow light that is then converted to blue light by the second light-emitting layer, effectively transferring the long service time characteristic to the blue light output. The microcavity structure with reflective portions enhances this conversion efficiency, achieving high blue light intensity with extended service time.
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 increases the intensity and extends the service time of blue light emission, enhancing the chromaticity coordinates of the OLED structure by compensating with converted blue light from green and red light-emitting layers, thereby improving the overall performance of AMOLED display devices.
Implementation Method 1
a charge generation layer (CGL) with a reflective portion, the CGL on the first light-emitting layer, the reflective portion having a transmission rate for light emitted by the first light-emitting layer
Implementation Method 2
a second electrode layer with a reflectivity on the second light-emitting layer
Implementation Method 3
a first light-emitting layer on the first electrode layer with one or more light-emitting portions for emitting light for compensating blue light
Data Source
AI summary
The present disclosure provides an organic light-emitting diode device (OLED) structure for compensating blue light emission. The OLED structure includes a substrate with a thin-film transistor layer, the substrate being substantially transparent; and a first electrode layer on the substrate, the first electrode being substantially transparent; a first light-emitting layer on the first electrode layer with one or more light-emitting portions for emitting light for compensating blue light. The OLED structure also includes a charge generation layer (CGL) with a reflective portion, the CGL on the first light-emitting layer, the reflective portion having a transmission rate for light emitted by the first light-emitting layer; a second light-emitting layer on the CGL with one or more light-emitting portions for emitting the blue light; and a second electrode layer with a reflectivity on the second light-emitting layer.