Silicon LED with DBR and Mesa Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current silicon-based LEDs have low emission efficiency and a wide emission spectrum due to difficulties in forming a p-type semiconductor doping layer and indirect doping of a distributed Bragg reflector (DBR) using insulating materials like silicon oxide and silicon nitride.
Innovation Solution
A silicon-based LED structure with a p-type mesa substrate and n-type doping layer sandwiched between an active layer and a DBR, where the DBR is composed of alternating silicon-containing insulating layers, allowing for high emission efficiency and narrow emission spectrum without direct doping into the DBR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a doping material is injected into a DBR to achieve high emission efficiency and narrow emission spectrum, then emission efficiency is improved, but the DBR structure is compromised because it is composed of insulating materials
Solution Approach 1:
The device is segmented into distinct functional regions: the DBR structure (first and second reflective layers) remains undoped and intact, while separate n-type doping layers are positioned adjacent to the active layer. This segmentation allows the DBR to maintain its insulating material composition and structural integrity while still achieving effective carrier injection through the adjacent doped regions.
2Manufacturing precision
If direct doping is performed into the DBR, then emission spectrum is narrowed, but manufacturing complexity increases due to the insulating nature of DBR materials
Solution Approach 1:
An n-type doping layer is introduced as an intermediary element between the external doping source and the active layer. This intermediary layer is positioned adjacent to the active layer and serves as the actual site for carrier injection, eliminating the need to perform direct doping into the insulating DBR materials while still achieving precise emission spectrum control.
3Strength
If alternating layers of silicon oxide and silicon nitride are used for DBR, then reflectance is improved, but doping becomes difficult due to the insulating properties of these materials
Solution Approach 1:
The device structure is divided into two independent functional systems: the DBR system (alternating silicon oxide and silicon nitride layers) that provides high reflectance, and the doping system (n-type doping layers) that provides carrier injection. By segmenting these functions into spatially separated components, the patent allows each system to optimize its performance without compromising the other.
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 structure achieves high emission efficiency, narrow emission spectrum, and improved electroluminescence characteristics by effectively injecting electrons and holes into the active layer using the n-type doping layer and DBR, enhancing light-emitting performance.
Implementation Method 1
A DBR is a multi-layer mirror composed of alternating layers of two materials having different refractive indices, and reflects light using the difference between the refractive indices of the layers.
Implementation Method 2
The silicon-based LED uses only the n-type doping layer to form a reflective layer on both surfaces of the active layer, thereby offering high emission efficiency, narrow emission spectrum, and improved electroluminescence characteristics.
Data Source
AI summary
Provided is a highly efficient silicon-based light emitting diode (LED) including a Distributed Bragg Reflector (DBR), an n-type doping layer, and a p-type substrate structure. The silicon-based LED includes: a substrate having a p-type mesa substrate structure; an active layer that is formed on the substrate and has a first surface and a second surface opposite the first surface; a first reflective layer facing the first surface of the active layer; a second reflective layer that is located on either side of the p-type substrate structure and faces the second surface of the active layer; an n-type doping layer sandwiched between the active layer and the first reflective layer; a first electrode electrically connected to the n-type doping layer; and a second electrode electrically connected to the p-type substrate structure.