Organic Semiconductor Laser Structure for Narrow Emission Peak Width
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Solution Overview
Problem
Existing organic solid-state semiconductor lasers and electroluminescent devices require improvements in laser efficiency, monochromaticity, and reduced peak width of the emission spectrum.
Innovation Solution
The configuration includes a hole injection section, electron injection section, and a light-emitting layer with a recombination-active region, where light propagates laterally, and employs hole- or electron-blocking layers to narrow the emission spectrum peak width, along with refractive index and thickness adjustments using absorption models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional light-emitting layer structure is used, then the device structure is simple, but the emission spectrum peak width is wide and laser efficiency is low
Solution Approach 1:
The light-emitting layer is segmented into multiple functional sub-layers: a hole injection layer adjacent to the hole injection electrode, a light-emitting layer proper containing the laser oscillation material, and an electron injection layer adjacent to the electron injection electrode. This segmentation allows each sub-layer to be optimized for its specific function, resulting in narrowed emission spectrum peak width and improved laser efficiency while maintaining overall device simplicity
Solution Approach 2:
Different regions of the light-emitting structure are assigned different material compositions and properties. The hole injection layer uses materials optimized for hole injection, the light-emitting layer proper contains the laser oscillation material at specific concentrations, and the electron injection layer uses materials optimized for electron injection. This local quality differentiation enables precise control of carrier distribution and recombination, achieving narrow emission peak width and high laser efficiency
2Illumination intensity
If the light-emitting layer thickness is increased, then the light emission intensity is improved, but the peak width of the emission spectrum increases
Solution Approach 1:
The light-emitting layer is divided into multiple sub-layers with different thicknesses. The light-emitting layer proper has an optimized thickness of 50-150 nm that balances emission intensity and peak width, while the hole injection layer and electron injection layer have different thicknesses optimized for their respective carrier injection functions. This segmentation allows the active light-emitting region to be thin enough for monochromaticity while still achieving high overall emission intensity through efficient carrier injection from the thicker injection layers
Solution Approach 2:
The thickness parameters of different layers are precisely controlled within specific ranges. The light-emitting layer proper is maintained at 50-150 nm to achieve narrow peak width, while the total thickness of the light-emitting structure is increased through the injection layers to maintain high emission intensity. This parameter optimization resolves the contradiction between intensity and peak width
3Productivity
If carrier injection is increased to improve laser efficiency, then the exciton density increases, but the emission spectrum peak width broadens
Solution Approach 1:
Carrier injection is segmented into separate hole injection and electron injection pathways through dedicated injection layers. This segmentation allows independent optimization of hole and electron injection rates, enabling precise control of carrier balance and exciton generation. The result is high laser efficiency through optimized recombination while maintaining narrow emission peak width through controlled carrier distribution
Solution Approach 2:
The injection layers are designed with specific material properties that create localized electric fields and carrier concentration gradients. The hole injection layer has properties optimized for hole injection, and the electron injection layer has properties optimized for electron injection. This local quality differentiation ensures that carriers are injected and recombine in a controlled manner, achieving high laser efficiency without excessive peak broadening
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 method significantly reduces the full-width half-maximum (FWHM) of the emission wavelength peak to 10 degrees or less and 10 nm or less, enhancing laser efficiency and monochromaticity.
Implementation Method 1
a light-emitting layer of emitting light by recombining holes and electrons
Implementation Method 2
an optical resonator that propagates the emitted light inside the light-emitting layer
Data Source
Figure 1(a)~2
Figure 3(a)~3(c)
Figure 4
AI summary
An organic solid-state semiconductor laser including a hole injection section, an electron injection section, a light-emitting layer of emitting light by recombining holes and electrons, and an optical resonator that propagates the emitted light inside the light-emitting layer, and including a hole-blocking layer on the electron injection section side of the light-emitting layer so as to be adjacent to the light-emitting layer or an electron-blocking layer on the hole injection section side of the light-emitting layer so as to be adjacent to the light-emitting layer has a small peak width of the emission spectrum.