Photodetector p-i-n Layer Structure for Low Dark Current
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Solution Overview
Problem
Current semiconductor photo-detecting devices face challenges in achieving optimal optical-electrical conversion efficiency and reducing dark current, which affects their performance in light sensing and communication applications.
Innovation Solution
The semiconductor photo-detecting device incorporates a substrate, first and second semiconductor layers with specific dopants, a light-absorbing layer, a semiconductor contact layer, and an insulating layer, along with a diffusion barrier layer, to form a p-i-n structure that enhances light absorption and reduces current leakage, thereby improving signal-to-noise ratio and photocurrent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional semiconductor structures are used, then device complexity is low, but optical-electrical conversion efficiency is insufficient
Solution Approach 1:
The semiconductor structure is divided into multiple functional layers including a first semiconductor layer with first dopant, a second semiconductor layer with second dopant, and a light-absorbing layer positioned between them. This segmentation allows each layer to perform its specific function optimally, improving optical-electrical conversion efficiency while managing complexity through modular design
Solution Approach 2:
Different regions of the semiconductor structure are doped with different dopants (first dopant in the first semiconductor layer, second dopant in the second semiconductor layer) to create localized electrical properties. The light-absorbing layer is strategically positioned to maximize light absorption in specific regions, achieving local optimization of optical-electrical conversion
2Reliability
If conventional semiconductor layers are used, then manufacturing is simple, but dark current is high
Solution Approach 1:
The semiconductor structure is segmented into a first semiconductor layer and a second semiconductor layer with different dopant configurations. This segmentation creates distinct functional regions that work together to suppress dark current while maintaining manufacturability through established semiconductor fabrication processes
Solution Approach 2:
The dopant concentration and type are varied across different semiconductor layers to optimize electrical properties. By changing the dopant parameters (first dopant vs. second dopant) in different layers, the structure achieves lower dark current while remaining compatible with conventional manufacturing techniques
3Reliability
If light-absorbing layer is added, then optical absorption is improved, but device complexity increases
Solution Approach 1:
The device structure is segmented to include a dedicated light-absorbing layer positioned between the first and second semiconductor layers. This segmentation isolates the light absorption function in a specific layer, improving overall optical absorption efficiency while allowing other layers to handle electrical functions
Solution Approach 2:
The light-absorbing layer serves multiple functions: it absorbs incident light to generate carriers, acts as a barrier to reduce dark current, and maintains structural integrity. This multi-functionality improves optical absorption without proportionally increasing device complexity
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 device exhibits improved optical-electrical characteristics, including low dark current and increased fabrication yield, making it suitable for applications in lighting control, medical care, and sensing systems.
Implementation Method 1
a light-absorbing device, such as a photovoltaic cell (PVC) or a photo-detecting device (PD), can convert light to electricity
Implementation Method 2
The first semiconductor layer is located on the substrate and includes a first dopant. The second semiconductor layer is located on the first semiconductor layer and includes a first region and a second region. The first region includes a second dopant and a third dopant
Data Source
AI summary
A photo-detecting device includes a first semiconductor layer with a first dopant, a light-absorbing layer, a second semiconductor layer, and a semiconductor contact layer. The second semiconductor layer is located on the first semiconductor layer and has a first region and a second region, the light absorbing layer is located between the first semiconductor layer and the second semiconductor layer and has a third region and a fourth region, the semiconductor contact layer contacts the first region. The first region includes a second dopant and a third dopant, the second region includes second dopant, and the third region includes third dopant. The semiconductor contact layer has a first thickness greater than 50 Å and smaller than 1000 Å.