Photosensor With Charge Blocking Layers For Capacitance Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photodetection elements require extraction of electric charges from photoelectric conversion layers to electrodes, which limits their efficiency and speed, and they often necessitate complex structures and reset operations.
Innovation Solution
A photosensor structure featuring a photoelectric conversion layer between two electrodes with blocking layers to suppress charge movement, allowing retained charges within the layer to increase permittivity and enable light detection through capacitance changes without charge extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electric charges are extracted from the photoelectric conversion layer to electrodes, then the photodetection element can generate electrical signal, but the detection speed and efficiency are limited and reset operations are required
Solution Approach 1:
Instead of extracting charges from the photoelectric conversion layer to electrodes as in conventional photodetectors, this patent inverts the approach by blocking charge extraction and allowing charges to accumulate within the photoelectric conversion layer. The blocking layers prevent charge movement to electrodes, causing accumulated charges to modulate the permittivity of the photoelectric conversion layer directly, which changes the capacitance between electrodes and generates detectable electrical signals without charge extraction.
Solution Approach 2:
The patent utilizes parameter changes in the permittivity of the photoelectric conversion layer as charges accumulate within it. The accumulated charges modify the electrical properties (permittivity) of the photoelectric conversion layer, which in turn changes the capacitance between the first and second electrodes. This parameter change approach enables signal generation without physical charge extraction, improving detection speed and eliminating the need for reset operations.
2Ease of operation
If conventional photodetection elements are used, then charge extraction is necessary for signal generation, but this requires complex structures and reset operations
Solution Approach 1:
The patent applies the inversion principle by blocking charge extraction instead of facilitating it. Conventional photodetectors use structures designed to extract charges to electrodes, while this patent uses blocking layers to prevent charge movement, allowing charges to remain in the photoelectric conversion layer and modulate permittivity, thereby simplifying the operational requirements and eliminating reset operations.
Solution Approach 2:
The patent extracts the charge extraction function from the device structure. Instead of having electrodes and associated structures designed to collect and extract charges, the patent removes this extraction mechanism and relies on the permittivity modulation effect of accumulated charges, thereby simplifying the overall device structure and operation.
3Productivity
If charges are retained within the photoelectric conversion layer, then permittivity increases and light detection is enabled through capacitance changes, but charge blocking layers are required
Solution Approach 1:
The patent segments the device into distinct functional layers: a photoelectric conversion layer for generating charges, blocking layers to prevent charge extraction, and electrodes for detecting capacitance changes. This segmentation allows each layer to perform its specific function optimally, with the blocking layers enabling charge retention and permittivity modulation while maintaining a relatively simple overall structure.
Solution Approach 2:
The blocking layers serve as intermediaries between the photoelectric conversion layer and the electrodes. They prevent direct charge extraction while allowing the photoelectric conversion layer to accumulate charges that modulate permittivity. The blocking layers mediate the interaction between generated charges and the external circuit, enabling detection through capacitance changes without direct charge transfer.
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
This configuration enhances light detection speed and efficiency by utilizing retained charges within the photoelectric conversion layer, reducing complexity and eliminating the need for reset operations, while maintaining sensitivity across various wavelengths.
Implementation Method 1
a photoelectric conversion layer between the first electrode and the second electrode, the photoelectric conversion layer generating electric charges by photoelectric conversion
Implementation Method 2
The first charge blocking layer is configured to suppress movement of holes from the photoelectric conversion layer to the first electrode and movement of electrons from the first electrode to the photoelectric conversion layer
Implementation Method 3
the second charge blocking layer is configured to suppress movement of electrons from the photoelectric conversion layer to the second electrode and movement of holes from the second electrode to the photoelectric conversion layer
Implementation Method 4
a voltage supply circuit configured to supply a voltage to the second electrode such that an electric field directed from the second electrode toward the first electrode is generated in the photoelectric conversion layer
Implementation Method 5
allowing retained charges within the layer to increase permittivity and enable light detection through capacitance changes
Data Source
AI summary
A photosensor including: a first electrode; a second electrode; a photoelectric conversion layer between the first electrode and the second electrode; a first charge blocking layer between the first electrode and the photoelectric conversion layer; a second charge blocking layer between the second electrode and the photoelectric conversion layer; a voltage supply circuit supplying a voltage to the second electrode such that an electric field directed from the second electrode toward the first electrode is generated in the photoelectric conversion layer; and a transistor. The first charge blocking layer suppresses movement of holes from the photoelectric conversion layer to the first electrode and movement of electrons from the first electrode to the photoelectric conversion layer, and the second charge blocking layer suppresses movement of electrons from the photoelectric conversion layer to the second electrode and movement of holes from the second electrode to the photoelectric conversion layer.