Light-Emitting Device Electrode Adhesion via Reactive Contact Material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light-emitting diodes face adhesion issues due to oxidation of adhesion layers like Ti or Cr, leading to peeling problems between electrode layers, which affects the reliability and performance of the devices.
Innovation Solution
The light-emitting device employs a contact material with higher reactivity than Pt, such as Be, Se, Sn, or Zn, integrated at specific depth positions within the electrode, along with a base material, to enhance adhesion and form an ohmic contact without using Ti or Cr, thereby improving the structural integrity and electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If Ti or Cr is used as adhesion layer material, then adhesion between electrode layers is improved, but the adhesion layer deteriorates due to oxidation and moisture, leading to peeling problems
Solution Approach 1:
The patent introduces an intermediary protective layer (such as Ni, Pd, or Pt) between the adhesion layer (Ti or Cr) and the environment. This intermediary layer acts as a barrier to moisture and oxygen, preventing oxidation of the adhesion layer while maintaining its adhesion function. The protective layer mediates between the need for strong adhesion and the need for oxidation resistance.
Solution Approach 2:
The patent creates an inert environment for the adhesion layer by enclosing it within protective barrier layers that exclude moisture and oxygen. This effectively isolates the reactive Ti or Cr adhesion layer from the corrosive environment, allowing it to maintain its adhesion properties without deteriorating over time.
2Strength
If conventional adhesion layers are used, then electrode layer bonding is achieved, but peeling occurs under stressful conditions like high temperature and humidity
Solution Approach 1:
The patent employs a composite electrode structure consisting of multiple layers with different functions: an adhesion layer (Ti or Cr) for bonding, a protective barrier layer (Ni, Pd, or Pt) for oxidation resistance, and optionally a conductive layer. This composite structure combines the advantages of each material to achieve both strong bonding and high stability under stressful conditions.
Solution Approach 2:
The patent applies a protective barrier layer in advance over the adhesion layer to cushion and protect it from environmental damage. This protective layer is applied beforehand to prevent oxidation and moisture ingress before they can cause deterioration, ensuring the adhesion layer maintains its bonding strength under high temperature and humidity conditions.
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 provides improved adhesion between electrode layers, maintaining electrical performance and preventing peeling, even under stressful conditions like high temperature and humidity, with a minimal increase in forward voltage after burn-in testing.
Implementation Method 1
a contact material in the semiconductor system and in the electrode, wherein the contact material has a largest intensity at a first depth position in the electrode
Implementation Method 2
elements such as Ti or Cr are easy to be oxidized and thus form metal oxides due to the moisture in the environment, and such chemical reaction of the elements results in deterioration of the adhesion layer
Data Source
AI summary
A light-emitting device is provided. The light-emitting device comprises: a semiconductor system comprising a light-emitting semiconductor stack; an electrode comprising a surface next to the semiconductor system; a contact material in the semiconductor system and in the electrode, wherein the contact material has a largest intensity at a first depth position in the electrode, and the contact material is selected from the group consisting of Be, Se, Sn, Zn, and combinations thereof; and a base material different from the base material and in the electrode.