Nanostructure Semiconductor Light Emitting Device Leakage Current Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nanostructure semiconductor light emitting devices face issues with leakage currents and increased operating voltages due to the thinness of active layers on tip portions, which can lead to dispersion of emitted light wavelengths and reduced luminous efficiency.
Innovation Solution
The device design includes a base layer with distinct regions, where tip portions of some nanostructures are not covered by the contact electrode, while others are covered, with a current blocking layer interposed between the contact electrode and nanostructures on one region, using insulating materials like SiO2 or SiN, to manage current flow and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact electrode covers the tip portion of the light emitting nanostructure, then the electrical connection is improved, but the leakage current increases and operating voltage increases
Solution Approach 1:
The contact electrode is designed with different coverage patterns for different regions: fully covering nanostructures on the second region (providing good electrical connection) and not covering tip portions of nanostructures on the first region (reducing leakage current). This local differentiation resolves the contradiction between electrical connection reliability and leakage current reduction.
2Reliability
If the contact electrode covers the tip portion of the light emitting nanostructure, then the electrical connection is improved, but the operating voltage increases
Solution Approach 1:
The contact electrode configuration is optimized locally: covering nanostructures on the second region for good electrical connection, and excluding tip portions of nanostructures on the first region to reduce operating voltage. This selective coverage resolves the contradiction between electrical connection quality and operating voltage level.
3Ease of manufacture
If the active layer on tip portion is thin, then the manufacturing is simplified, but the leakage current increases and wavelength dispersion occurs
Solution Approach 1:
The harmful tip portion of the active layer is extracted or removed by not covering it with the contact electrode. This eliminates the source of leakage current and wavelength dispersion while maintaining the simplified manufacturing process for the thin active layer on the nanocore.
Solution Approach 2:
Different regions of the light emitting nanostructure are treated differently: the tip portion (on first region) is left uncovered to avoid leakage and wavelength dispersion, while the main body (on second region) is covered for good electrical connection. This local differentiation resolves the contradiction between manufacturing simplicity and emission reliability.
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
This approach reduces leakage currents and operating voltages, stabilizes light emission characteristics, and enhances luminous efficiency by controlling current flow and preventing unwanted light emission from certain nanostructure regions.
Implementation Method 1
The plurality of light emitting nanostructures disposed on the second region and the contact electrode may include a current blocking layer interposed therebetween
Implementation Method 2
an insulating protective layer filling a space between the plurality of light emitting nanostructures
Implementation Method 3
energy generated through electron-hole recombination is converted into light to be emitted therefrom
Data Source
AI summary
A nanostructure semiconductor light emitting device may includes: a base layer having first and second regions and formed of a first conductivity-type semiconductor material; a plurality of light emitting nanostructures disposed on an upper surface of the base layer, each of which including a nanocore formed of the first conductivity-type semiconductor material, and an active layer and a second conductivity-type semiconductor layer sequentially disposed on the nanocore; and a contact electrode disposed on the plurality of light emitting nanostructures, wherein a tip portion of each of light emitting nanostructures disposed on the first region may not be covered with the contact electrode, and a tip portion of each of light emitting nanostructures disposed on the second region may be covered with the contact electrode.