Vertical Cavity Light Emitting Device Mixed Composition Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vertical cavity surface emitting lasers face challenges in efficiently injecting current to the light emitting layer without loss, leading to high lasing threshold currents and reduced manufacturing yield.
Innovation Solution
A vertical cavity light emitting device is designed with a first multilayer film reflector, a semiconductor structure layer, an insulating current confinement layer with a through opening, a transparent electrode covering the opening, and a mixed composition layer formed at the edge of the opening, where the current confinement layer and transparent electrode are mixed, to enhance current injection and reduce threshold current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional insulation layer with opening is used for current injection, then the device structure is simple, but the threshold current is high and manufacturing yield is low
Solution Approach 1:
The patent employs a composite structure combining insulating material (silicon oxide layer) with conductive material (transparent electrode) to form a mixed composition layer. This composite approach allows the insulating layer to provide electrical isolation while the conductive electrode enables efficient current injection, resolving the contradiction between structural simplicity and manufacturing reliability.
Solution Approach 2:
The patent creates a localized mixed composition layer only at the edge of the through opening where the insulating layer and transparent electrode interface. This local modification provides enhanced current injection properties precisely where needed (at the opening edge) while maintaining the insulating properties of the bulk insulation layer, thereby improving manufacturing yield without complicating the overall device structure.
2Device complexity
If current injection efficiency is poor, then device structure is simple, but threshold current is high
Solution Approach 1:
The mixed composition layer formed by combining insulating material and conductive transparent electrode creates a region with optimized electrical properties. This composite structure enhances current injection efficiency into the active layer, directly reducing the threshold current despite the increased structural complexity of the current confinement layer.
Solution Approach 2:
The mixed composition layer acts as an intermediary region between the insulating current confinement layer and the conductive transparent electrode. This intermediate structure facilitates efficient current transfer from the electrode to the active layer while maintaining electrical isolation from surrounding regions, thereby reducing threshold current.
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 the threshold current and improves manufacturing yield by ensuring efficient current injection and uniform light emission, while also allowing for the adjustment of threshold current values during manufacturing.
Implementation Method 1
a mixed composition layer that is formed so as to be in contact with an edge of the through opening and in which the current confinement layer and the transparent electrode are mixed
Implementation Method 2
a first multilayer film reflector formed on a substrate; a second multilayer film reflector formed on the transparent electrode
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A vertical cavity light emitting device (10) includes: a first multilayer film reflector (13); a semiconductor structure layer that is formed on the first multilayer film reflector and includes a first conductivity type semiconductor layer (15) , an active layer (17), and a second conductivity type semiconductor layer (19); an insulating current confinement layer (21) formed on the second conductivity type semiconductor layer; a through opening formed in the current confinement layer; a transparent electrode (23) for covering the through opening and the current confinement layer, the transparent electrode being in contact with the second conductivity type semiconductor layer through the through opening; a second multilayer film reflector (25) formed on the transparent electrode; and a mixed composition layer (24) formed to be in contact with an edge of the through opening and in which the current confinement layer and the transparent electrode are mixed.