Light-Emitting Device Rear Absorption Layer
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Solution Overview
Problem
Light-emitting devices with a light-transmitting type configuration face issues with light leakage from the rear surface, which reduces light extraction efficiency from the front surface and impairs visibility from the rear side.
Innovation Solution
Incorporating a light-transmitting region between light-emitting units with a second base material that includes an absorption layer, which has a higher light absorption ratio at specific wavelengths, particularly between 400 nm and 700 nm, to selectively absorb light and reduce leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light-transmitting type configuration is used with the second electrode only in a portion of a pixel, then optical transparency is improved, but light leaks out from the rear surface reducing light extraction efficiency
Solution Approach 1:
An absorption layer is introduced as an intermediary component between the light-emitting units and the rear surface. This absorption layer selectively absorbs light that would otherwise leak from the rear surface, thereby resolving the contradiction between maintaining optical transparency and preventing light leakage. The absorption layer acts as a mediator that allows the light-transmitting configuration to function while eliminating its harmful side effect.
2Loss of information
If the second base material is made light-transmitting to maintain visibility, then visibility from the rear side is improved, but light leakage from the rear surface increases
Solution Approach 1:
The absorption layer is positioned specifically at the rear base material where light leakage occurs, creating a localized solution. The light-transmitting first base material maintains visibility, while the light-absorbing second base material selectively addresses the harmful light leakage. This local differentiation of properties resolves the contradiction between maintaining visibility and preventing light leakage.
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 absorption layer effectively minimizes light leakage from the rear surface, enhancing light extraction efficiency from the front surface and maintaining optical transparency while ensuring visibility from the rear side.
Implementation Method 1
the absorption layer has a higher light absorption ratio at the first wavelength than an average light absorption ratio within a wavelength range of equal to or higher than 400 nm and equal to or lower than 700 nm
Data Source
AI summary
A light-emitting device (10) includes a light-transmitting first base material (210), a light-transmitting second base material (220), and a plurality of light-emitting units (140). The light-emitting units (140) are located between the first base material (210) and the second base material (220). The light-emitting units (140) emit light having a peak at a first wavelength. In addition, the light-emitting device (10) includes a light-transmitting region located between the plurality of light-emitting units (140). Further, the second base material (220) includes an absorption layer (170). The absorption layer (170) is a layer that particularly absorbs light of the first wavelength.