Ag Reflective Layer with Oxide Particles for Semiconductor Light Extraction
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Solution Overview
Problem
Existing semiconductor light emitting devices face challenges in achieving high light extraction efficiency and reliable adhesion between dielectric multilayered films and reflective layers, which affects their performance and longevity.
Innovation Solution
A semiconductor element and device design that incorporates a reflective layer with Ag as a major component, containing particles of oxides, nitrides, or carbides, which enhances adhesion and reflectance by forming a pseudo transition layer at the interface with the dielectric multilayered film, eliminating the need for additional adhesion layers and reducing light absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a dielectric multilayered film is disposed in contact with the reflective surface of the Ag reflective layer, then light reflection is facilitated, but adhesion between the dielectric multilayered film and the reflective layer deteriorates
Solution Approach 1:
A TiO2 layer is introduced as an intermediary between the dielectric multilayered film and the Ag reflective layer. This TiO2 layer serves as an adhesion promoter that chemically bonds to both the dielectric film and the Ag surface, resolving the adhesion problem while preserving the optical reflection properties of the Ag layer.
Solution Approach 2:
The surface properties of the Ag reflective layer are modified by forming a TiO2 layer through controlled oxidation. This changes the chemical composition and surface energy parameters of the Ag surface, enabling better adhesion to the dielectric multilayered film while maintaining the underlying Ag's high reflectivity.
2Reliability
If a Ni thin film is interposed between the dielectric multilayered film and the Ag reflective layer to improve adhesion, then adhesion is improved, but light absorption increases and reflectance decreases
Solution Approach 1:
Instead of using Ni which has high light absorption, a TiO2 layer is used which has high transparency in the visible range. This changes the material parameter from a metal (Ni) to a ceramic oxide (TiO2), achieving adhesion improvement without sacrificing optical performance.
Solution Approach 2:
The reflective layer is designed as a composite structure combining Ag (for high reflectivity) and TiO2 (for adhesion promotion). This composite approach allows both materials to contribute their respective advantages: Ag provides optical reflection while TiO2 provides adhesion to the dielectric film.
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 achieves improved adhesion and high reflectance, leading to increased light emission intensity and luminous flux, while maintaining the smoothness and heat dissipation properties of the reflective layer, thus enhancing the overall performance of the semiconductor light emitting device.
Implementation Method 1
there are methods for reflecting the light emitted by the active layer, such as by providing a reflective layer to thereby increase the light extraction efficiency
Implementation Method 2
a dielectric multilayered film disposed in contact with the reflective surface of the reflective layer for facilitating the reflection of light
Data Source
AI summary
A semiconductor light emitting element is provided. The semiconductor light emitting element has a semiconductor stack, an n-side conductor layer, a p-side conductor layer, a dielectric multilayered film, an n-side reflective layer and a p-side reflective layer, disposed in that order. The n-side and p-side reflective layers contain Ag as a major component and contain particles of at least one selected from an oxide, a nitride, and a carbide.