Perovskite Quantum Dot Light Emitting Diode with Surface Passivation
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Solution Overview
Problem
Perovskite quantum dots (PeQDs) applied as a single material to the photo-active layer of organic light emitting devices exhibit only single-colored light and face challenges in producing multicolored light and large-area devices through solution processes, limiting their performance and functionality.
Innovation Solution
A quantum dot light emitting diode (QLED) with an invert structure is developed, featuring a surface-passivated quantum dot layer using perovskite quantum dots (PeQDs) with a short chain ligand, where the quantum dot layer includes a surface-passivated PeQD with a specific chemical structure and a passivation layer formed through a solid-state ligand exchange reaction, enhancing the surface passivation ratio and photoemission properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If perovskite quantum dots are applied as a single material to the photo-active layer, then the device structure is simple, but only single colored light is exhibited and multicolored light emission is difficult to achieve
Solution Approach 1:
The photo-active layer is segmented into multiple quantum dot layers, each containing quantum dots with different band gaps. This segmentation allows each layer to emit different colored light, achieving multicolored light emission while maintaining a relatively simple overall device structure through solution process fabrication
2Ease of manufacture
If perovskite quantum dots are applied as a single material, then the manufacturing process is simple, but large-area device production through solution process is difficult
Solution Approach 1:
The device is divided into multiple quantum dot layers that can be fabricated separately through solution process and then stacked together. This segmentation enables scalable manufacturing of large-area devices while maintaining the simplicity of solution process fabrication for each individual layer
Solution Approach 2:
The invention transitions from planar single-layer fabrication to vertical multi-layer stacking in the thickness dimension. By fabricating multiple thin quantum dot layers through solution process and stacking them vertically, large-area devices can be produced while maintaining manufacturing simplicity
3Device complexity
If perovskite quantum dots are used without surface passivation, then the synthesis process is simple, but the surface passivation ratio is low and photoemission properties are poor
Solution Approach 1:
Surface passivation is performed as a preliminary action during the quantum dot synthesis process. By incorporating surface passivation ligands into the synthesis procedure, the quantum dots are prepared with improved surface passivation ratios before being assembled into the photo-active layer, enhancing photoemission properties without significantly complicating the overall synthesis process
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 QLED with surface-passivated PeQDs achieves improved performance by exhibiting multicolored light emission and stable operation, surpassing the limitations of general organic light emitting diodes with high surface passivation ratios and uniform thin film formation, enabling efficient and effective quantum dot light emitting diodes.
Implementation Method 1
a surface treatment layer positioned on a surface of the quantum dot and including an organic ligand represented by the following Chemical Formula 2 and an organic ligand represented by the following Chemical Formula 3
Implementation Method 2
a material based on a perovskite structure has excellent optoelectronic properties such as being able to realize a narrow half width at half maximum (HWHM) while realizing various band gaps and a high photoluminescent quantum yield (PL-QY)
Data Source
AI summary
There are provided a quantum dot light emitting diode based on a quantum dot of which a surface is passivated with a short chain ligand, and a method of manufacturing the same.