Micro LED Insulation Region for Surface Recombination Control
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Solution Overview
Problem
Micro LEDs face challenges in luminous efficiency due to non-radiative surface recombination, especially with small sizes, which affects their ability to display images effectively and requires improved mounting processes.
Innovation Solution
The development of a light emitting device structure with a conductivity type semiconductor layer, an active layer, and a side surface insulation region formed by ion implantation, which prevents current leakage and enhances luminous efficiency by reducing non-radiative surface recombination, and includes a mesa structure with a surface protection layer for improved mounting on a circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If micro LEDs are used to achieve small pixel size, then display resolution is improved, but handling difficulty increases and non-radiative surface recombination increases
Solution Approach 1:
The micro LED is segmented into multiple functional regions: an active region for light emission and an insulation region for preventing surface recombination. The insulation region is formed by ion implantation or oxidation processes, creating distinct functional zones within the micro LED structure that address both resolution requirements and surface recombination issues.
Solution Approach 2:
Different regions of the micro LED are given different properties: the active region maintains high conductivity for carrier injection and recombination, while the insulation region has modified surface properties through ion implantation or oxidation to prevent non-radiative surface recombination. This local differentiation optimizes both light emission efficiency and surface recombination prevention.
2Measurement precision
If micro LEDs are made smaller to increase pixel density, then display resolution is improved, but luminous efficiency decreases due to non-radiative surface recombination
Solution Approach 1:
The surface recombination issue, which normally causes energy loss, is converted into a beneficial effect by creating an insulation region that selectively blocks non-radiative recombination paths. The ion implantation or oxidation process modifies the surface to convert harmful surface recombination centers into beneficial insulating barriers, thereby reducing energy loss and improving luminous efficiency.
Solution Approach 2:
The surface properties of the micro LED are changed through ion implantation or oxidation processes, modifying the surface state from conductive to insulating. This parameter change in surface conductivity prevents non-radiative surface recombination and improves the overall luminous efficiency of the micro LED, addressing the energy loss issue while maintaining small size for high resolution.
3Reliability
If ion implantation is used to form insulation region, then non-radiative surface recombination is prevented, but manufacturing complexity increases
Solution Approach 1:
The insulation region is formed during the manufacturing process through ion implantation or oxidation steps performed on the micro LED structure before final assembly. This preliminary action of modifying the surface properties during fabrication ensures that the insulation region is pre-formed to prevent surface recombination, integrating the complexity into the manufacturing process rather than requiring additional complex assembly steps.
4Ease of manufacture
If GaAs or GaP-based red LEDs are used, then color display is achieved, but carrier diffusion distance increases leading to higher non-radiative surface recombination
Solution Approach 1:
The insulation region acts as an intermediary barrier between the active region and the external environment. It mediates the interaction at the surface by blocking non-radiative recombination paths, thereby protecting the carrier diffusion process in the GaAs or GaP-based red LED from surface recombination losses, thus maintaining quantum efficiency while enabling color display.
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 solution effectively prevents non-radiative surface recombination, enhances luminous efficiency, and simplifies the mounting process for micro LEDs, enabling more efficient image display and improved performance in display apparatuses.
Implementation Method 1
the insulation region includes implanted ions
Implementation Method 2
an oxidation region forming layer interposed between the second conductivity type semiconductor layer and the active layer, in which the light emitting structure includes a side surface exposing the active layer
Data Source
AI summary
A light emitting device for a display including a light emitting structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, and having a side surface exposing the active layer, in which a portion of the second conductivity type semiconductor layer and the active layer along an edge of the light emitting structure is insulative in a thickness direction to define an insulation region, and the insulation region includes implanted ions.