Micro LED Sidewall Barrier Layer for Leakage Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Micro light-emitting diodes (LEDs) with sizes less than 10 μm experience reduced external quantum efficiency due to increased leakage current and non-radiative recombination at their sidewalls, which existing manufacturing methods, such as mild dry etching and passivation films, fail to adequately address.
Innovation Solution
A light-emitting diode structure incorporating a barrier layer on the side faces of semiconductor layers to form a charge depletion region, reducing lateral current and non-radiative recombination by creating a high resistance area, thereby enhancing external quantum efficiency. The barrier layer is designed with specific work functions and materials like metal, conductive metal oxides, graphene, or metallic carbon nanotubes to effectively suppress carrier leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the light-emitting diode size is reduced to less than 10 μm, then the display resolution is improved, but the external quantum efficiency deteriorates due to increased leakage current and non-radiative recombination at sidewalls
Solution Approach 1:
The patent applies local quality by forming a barrier layer specifically on the sidewalls of the semiconductor layers. This barrier layer has different electrical properties (higher resistance) compared to the bulk semiconductor material, creating a localized charge depletion region that suppresses carrier leakage at the sidewalls while leaving the active region unaffected. This resolves the contradiction by improving sidewall properties without changing the overall device size.
Solution Approach 2:
The barrier layer acts as an intermediary between the semiconductor layers and the external environment. It mediates the carrier transport by creating a charge depletion region that blocks lateral carrier leakage, thereby protecting the light-emitting region from carrier loss while maintaining the small device dimensions necessary for high resolution.
2Reliability
If a barrier layer is formed on the sidewalls to suppress leakage current, then the external quantum efficiency is improved, but the device structure becomes more complex
Solution Approach 1:
The barrier layer is implemented as a thin film structure that conforms to the sidewall geometry of the semiconductor layers. This thin film approach adds minimal structural complexity while effectively suppressing carrier leakage. The barrier layer can be deposited using standard thin film techniques, integrating smoothly into the existing manufacturing process without requiring complex three-dimensional structures.
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 charge depletion region effectively reduces leakage current and enhances luminescence efficiency by concentrating carriers away from the sidewalls, improving the external quantum efficiency of micro LEDs.
Implementation Method 1
The barrier layer is configured to form a charge depletion region between the barrier layer and the at least part of the side face
Implementation Method 2
A work function of the first barrier layer is less than a work function of the P-type semiconductor layer
Data Source
AI summary
A light-emitting diode includes a first semiconductor layer, a second semiconductor layer, a light-emitting layer disposed between the first semiconductor layer and the second semiconductor layer, and a barrier layer disposed on at least part of a side face of at least one of the first semiconductor layer and the second semiconductor layer. The barrier layer is configured to form a charge depletion region between the barrier layer and the at least part of the side face.