Pyramidal Nanorod LED Structure for Stable Display Color
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Solution Overview
Problem
Existing display apparatuses face challenges in reducing manufacturing costs and improving color reproducibility due to the use of LEDs, particularly when implementing all RGB colors without a color filter, and current injection causes wavelength variations in nanorod LEDs.
Innovation Solution
The development of nanorod LEDs with a pyramidal structure, including a first-type semiconductor layer, a nitride light emitting layer, and a second-type semiconductor layer, stacked to form a nanorod with specific diameter and thickness ratios, utilizing semi-polar planes to reduce wavelength variation and enhance color reproducibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If nanorod LEDs are used to reduce manufacturing costs and eliminate color filters, then manufacturing cost is reduced and device complexity is simplified, but wavelength variation due to current injection deteriorates color reproducibility
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the central core region and surrounding shell region have different compositions and properties. The core region contains a first nitride semiconductor layer with specific composition while the shell region contains a second nitride semiconductor layer with different composition, allowing each region to address specific issues: the core provides primary light emission while the shell compensates for wavelength shifts, thus improving color reproducibility while maintaining the nanorod LED's manufacturing advantages
Solution Approach 2:
The patent employs composite materials by combining different nitride semiconductor materials with varying bandgaps in a core-shell configuration. The first nitride semiconductor (core) and second nitride semiconductor (shell) form a composite structure where the shell material is selected to have a smaller bandgap than the core, enabling the shell to emit light at longer wavelengths and compensate for the blue-shift caused by current injection in the core, thereby resolving the color reproducibility issue while maintaining cost-effectiveness
2Illumination intensity
If current injection is increased to enhance light emission intensity, then illumination intensity is improved, but wavelength change increases causing color reproducibility to deteriorate
Solution Approach 1:
The patent implements a feedback mechanism through the core-shell structure where the shell region responds to wavelength shifts caused by current injection. As current increases and causes blue-shift in the core emission, the shell region's emission at longer wavelengths compensates for this shift, providing a self-regulating effect that maintains color reproducibility across varying current levels and illumination intensities
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 nanorod LEDs achieve improved color reproducibility and reduced manufacturing costs by minimizing wavelength changes due to current injection, enabling high-resolution displays without the need for color filters.
Implementation Method 1
a nitride light emitting layer provided on the pyramidal structure
Data Source
AI summary
Provided are nanorod light emitting diodes (LEDs), display apparatuses, and manufacturing methods thereof. The nanorod LED includes a first-type semiconductor layer including a body and a pyramidal structure continuously provided from the body, a nitride light emitting layer provided on the pyramidal structure, and a second-type semiconductor layer provided in the nitride light emitting layer.