Two-Terminal Semiconductor Light Emitter Using Tunnel Junction
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Solution Overview
Problem
Existing semiconductor devices, such as diode lasers, face limitations in operating speed due to charge-photon interaction and resonance peaks, which restrict their linear frequency response and efficiency in light emission and laser production.
Innovation Solution
A two-terminal semiconductor device with a terminal-less base region exhibiting quantum size effects and a tunnel junction between the emitter and collector regions, where the EM field confinement is optimized to enhance stimulated recombination, allowing for faster light emission and laser production by avoiding the slow and poorly conducting hole injection and transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional diode laser structure is used with hole injection and transport, then light emission can be achieved, but operating speed is limited due to slow and poorly conducting hole transport
Solution Approach 1:
The patent extracts and eliminates the hole injection and transport mechanism from the device structure. By using a tunnel junction that directly generates electron-hole pairs at the base-collector depletion region, the invention removes the need for separate hole injection and transport processes, thereby achieving high-speed operation without the limitations of hole conduction
Solution Approach 2:
The patent introduces a tunnel junction as an intermediary mechanism between the emitter and collector. This tunnel junction serves as a direct generator of electron-hole pairs that recombine in the base quantum wells, replacing the conventional indirect hole transport path and enabling faster operation
2Productivity
If EM field confinement is optimized in conventional diode lasers, then light emission efficiency improves, but resonance peaks appear that limit linear frequency response
Solution Approach 1:
The patent applies local quality by creating a specific spatial distribution of the electromagnetic field through the tunnel junction structure. The EM field is confined to the base quantum wells where electron-hole recombination occurs, while the tunnel junction itself is positioned to generate carriers locally without creating resonant cavities that would limit frequency response
Solution Approach 2:
The device is segmented into distinct functional regions: the tunnel junction for carrier generation, the base quantum wells for recombination and light emission, and the collector for collection. This segmentation allows optimization of each region's function while avoiding the resonance problems that arise in monolithic conventional laser structures
3Speed
If tunnel junction is used to generate electron-hole pairs directly, then operating speed increases, but device structure becomes more complex
Solution Approach 1:
The patent merges the functions of carrier injection and carrier generation into a single tunnel junction structure. The tunnel junction simultaneously serves as the interface between emitter and collector and as the direct source of electron-hole pairs, reducing the number of separate components needed while achieving high-speed operation
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 enables higher speed operation and improved light emission and laser production by shifting EM field confinement into the collector body, maximizing recombination at the base quantum wells, and eliminating resonance peaks, resulting in devices that can operate beyond conventional speed limitations.
Implementation Method 1
a tunnel junction between the emitter and collector regions
Implementation Method 2
the base region having a region therein exhibiting quantum size effects
Implementation Method 3
causes light emission from said base region
Implementation Method 4
an optical cavity encloses at least a portion of the base region, and said light emission comprises laser emission
Data Source
AI summary
A two terminal semiconductor device for producing light emission in response to electrical signals, includes: a terminal-less semiconductor base region disposed between a semiconductor emitter region and a semiconductor collector region having a tunnel junction adjacent the base region; the base region having a region therein exhibiting quantum size effects; an emitter terminal and a collector terminal respectively coupled with the emitter region and the collector region; whereby application of the electrical signals with respect to the emitter and collector terminals, causes light emission from the base region. Application of the electrical signals is operative to reverse bias the tunnel junction. Holes generated at the tunnel junction recombine in the base region with electrons flowing into the base region, resulting in the light emission. The region exhibiting quantum size effects is operative to aid recombination.