Graded InGaAsP Semiconductor Light Receiving Device
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Solution Overview
Problem
Existing semiconductor light receiving devices face challenges in achieving high photoelectric conversion efficiency and high-speed response under low voltage and high power conditions, particularly in 40 G/100 Gbps optical communication systems, while also requiring miniaturization and low power consumption.
Innovation Solution
A semiconductor light receiving device is designed with a p-n junction formed at the interface between a p-type semiconductor layer and a cathode region, utilizing a monotonically changing electric field intensity to enhance electron-hole pair migration, and incorporating a light absorbing region with varying acceptor concentrations to optimize electric field distribution and carrier density profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the light receiving device is miniaturized and operated at low voltage to reduce power consumption, then power consumption and device size are reduced, but photoelectric conversion efficiency and response speed deteriorate
Solution Approach 1:
The patent changes the physical parameters of the semiconductor layers by introducing graded composition layers (InGaAsP layers with gradually changing composition ratios) to optimize the band structure and electric field distribution. This allows efficient photoelectric conversion at low operating voltages by enhancing carrier generation and separation without requiring high power input
Solution Approach 2:
The patent applies different composition ratios and doping concentrations at different locations within the light receiving device. The graded InGaAsP layers have locally optimized properties where the composition ratio changes gradually from one layer to another, creating localized electric fields that enhance carrier separation efficiency specifically in the light absorption region while maintaining low overall power consumption
2Volume of moving object
If the light receiving device is miniaturized to reduce device size, then device size is reduced, but photoelectric conversion efficiency and response speed deteriorate
Solution Approach 1:
The patent modifies the compositional parameters of the semiconductor layers using graded InGaAsP structures with varying sulfur concentrations and metal compositions. These parameter changes optimize the absorption coefficient and carrier mobility within the compact device volume, enabling fast response speeds despite miniaturization
Solution Approach 2:
The patent introduces compositional grading as an additional dimension of control within the device structure. By varying the composition ratio and doping concentration as a function of depth through the graded layers, the patent creates a three-dimensional optimization space that maintains high performance in a reduced device volume
3Speed
If high power signal light is incident to achieve high-speed response, then response speed is improved, but power consumption increases
Solution Approach 1:
The patent optimizes the bandgap energy parameters and doping concentrations in the graded InGaAsP layers to enhance the quantum efficiency of photoelectric conversion. This allows the device to achieve high response speeds by effectively converting even low-power incident light into electrical signals, reducing the need for high input power
Solution Approach 2:
The patent replaces the reliance on high mechanical/power input with an optimized electromagnetic field structure through graded composition layers. The gradual composition change creates optimized electric field distributions that enhance carrier separation and collection efficiency, achieving high response speeds through field optimization rather than power input
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 achieves high quantum efficiency and high-speed response to optical signals at low driving voltages, ensuring effective operation in high-speed communication systems with reduced power consumption and miniaturized design.
Implementation Method 1
light incident through the incident surface of the substrate enters the optical absorption layer and is converted into an electric signal at the p-n junction
Data Source
AI summary
A semiconductor light receiving device includes a substrate having an incident surface receiving light incident on the semiconductor light receiving device and a principal surface opposite to the incident surface; a first semiconductor layer disposed on the principal surface of the substrate, the first semiconductor layer defining one of a cathode region and an anode region; a light absorbing region disposed on the first semiconductor layer; and a second semiconductor layer disposed on the light absorbing region, the second semiconductor layer defining the other of the cathode region and the anode region and forming a junction with the light absorbing region. The light absorbing region includes a semiconductor layer having a conductivity type opposite to the conductivity type of the first semiconductor layer. The semiconductor layer of the light absorbing region forms a p-n junction with the first semiconductor layer.