Axial PbTe/CdTe Photoelectric Element for Wide-Spectrum Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Photoelectric elements tuned to a single wavelength are not adaptable for a wider spectrum, and high voltages are often required for efficient operation.
Innovation Solution
An active photoelectric element with a layered structure featuring a cone-shaped PbTe/CdTe quantum well, where the PbTe layer varies in thickness radially, allowing wide spectral sensitivity without the need for high voltages, combined with a movable lens for selective wavelength focusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photoelectric elements are tuned to a single wavelength, then detection precision at that wavelength is improved, but adaptability to wider spectrum deteriorates
Solution Approach 1:
The patent applies local quality by creating radial variation in the active layer thickness within a single detector structure. The center region has different thickness than the peripheral regions, allowing different parts of the same detector to respond to different wavelengths. This enables a single device to detect multiple wavelengths simultaneously with maintained precision at each wavelength.
Solution Approach 2:
The invention achieves universality by designing a single photoelectric detector that can detect radiation across a wide spectral range (0.775 µm to 6.5 µm). By incorporating radial thickness variation in the active layer, one detector structure performs multiple wavelength detection functions that would traditionally require multiple separate detectors tuned to specific wavelengths.
2Measurement precision
If high voltages are applied for efficient operation, then detection sensitivity is improved, but energy consumption increases
Solution Approach 1:
The patent applies parameter changes by varying the thickness parameter of the active layer radially across the detector structure. This geometric parameter variation optimizes the photoelectric conversion efficiency at different wavelengths and positions, enabling high detection sensitivity across the entire spectral range without requiring high operating voltages. The optimized thickness distribution enhances carrier collection efficiency, reducing the need for high voltage application.
3Measurement precision
If quantum well structures are used to enhance sensitivity, then detection sensitivity is improved, but manufacturing complexity increases
Solution Approach 1:
The invention applies segmentation by dividing the active layer into multiple regions with different thicknesses (center region and peripheral regions). This segmented approach allows each region to be optimized for specific wavelength ranges while maintaining a relatively simple overall structure. The radial segmentation achieves enhanced sensitivity across broad spectrum without requiring complex multi-layer quantum well structures.
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
Enables detection and generation of radiation across a wide wavelength range from 0.775 µm to 6.5 µm with low voltage requirements, enhancing operational flexibility and efficiency.
Implementation Method 1
Varying thickness of lead telluride layer allows a use of photoelectric effect in a wide frequency band or wavelength range
Implementation Method 2
The depth of the quantum well U in a multilayer heterostructure depends on the difference in the energy of the band gaps Eg1 and Eg2 of the pair of semiconductors
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Axial active photoelectric element having layered structure stacked along a first axis (O) and comprising a first electrode (141) and a second electrode (142), wherein the layered structure. A layer of lead telluride (130) disposed between two layers of cadmium telluride (121, 122) is an active layer. The layer of lead telluride (130) has a radially varying thickness and forms at least part of the lateral surface of cone.