Micro LED Reflective Layer for Sidewall Light Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Inorganic micro LEDs suffer from light loss due to emitted light with large angles being blocked in augmented reality devices, reducing overall light emitting efficiency.

Innovation Solution

A micro LED structure incorporating a light emitting structure, a passivation layer, a reflective layer, and an electrical conductive layer is designed to reflect light from the sidewalls back to the top surface, minimizing loss and enhancing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional micro LED structure is used, then manufacturing is simple, but light emitting efficiency is reduced due to light loss from sidewalls

Engineering Contradiction:

Improvelight loss from sidewallsVSAvoidstructure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent converts the harmful light loss from sidewalls into a beneficial effect by introducing a reflective layer that redirects the escaped light back to the top surface, transforming energy loss into useful light output and improving overall light emitting efficiency

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The reflective layer acts as an intermediary element between the light emitting structure and the external environment, intercepting light that would otherwise be lost and redirecting it toward the useful emission direction, thereby reducing energy loss without fundamentally changing the core LED structure

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If reflective layer is added to reduce light loss, then light emitting efficiency is improved, but device complexity increases

Engineering Contradiction:

Improvelight emitting efficiencyVSAvoidnumber of layers

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The reflective layer is applied selectively to specific regions where light loss occurs (sidewalls), rather than uniformly across the entire device, allowing targeted improvement of light emitting efficiency in critical areas while minimizing overall structural complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs a composite structure combining the light emitting semiconductor material with a reflective layer material, creating a multi-functional structure that simultaneously performs light emission and light redirection functions, thereby improving efficiency with minimal additional complexity

Inventive Principle:

Principle #40Composite materials

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 reduces light loss from sidewalls, improving the overall light emitting efficiency by reflecting light back to the top surface, ensuring that substantially all light is emitted without being blocked in devices like AR devices.

Implementation Method 1

a reflective layer formed on the passivation layer... effectively reduces light loss from sidewalls, improving the overall light emitting efficiency by reflecting light back to the top surface

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS20230282781A1Micro LED, micro LED panel and micro LED chip

Publication Date: 2023.09.07 JADE BIRD DISPLAY (SHANGHAI) LTD

AI summary

A micro LED includes a light emitting structure; a passivation layer formed on the light emitting structure; a reflective layer formed on the passivation layer; and an electrical conductive layer formed on the top surface of the passivation layer and on the top surface of the reflective layer.