Organic Pixeled Flat Detector Pixel-Level Preamplification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inorganic flat detectors are expensive and complex due to the use of PIN diodes, and they require additional components like resistors and precise current sources, making them uneconomical for large-scale production and use in medical imaging applications.
Innovation Solution
A cost-effective pixeled flat detector design incorporating organic photodiodes, reset transistors, amplifying transistors, and read transistors, where organic photodiodes are connected to a common supply voltage and directly to the gate of amplifying and reset transistors, with preamplification at the pixel level to reduce noise contributions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inorganic PIN diodes are used in flat detectors, then sensitivity and detection capability are improved, but manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent replaces expensive inorganic PIN diodes with organic photodiodes that can be manufactured cost-effectively using solution processing methods. The organic photodiodes achieve sufficient detection capability for medical imaging applications while dramatically reducing manufacturing costs and device complexity, making large-scale production economically viable
Solution Approach 2:
The patent changes the material parameters from inorganic to organic semiconductors, utilizing organic materials with appropriate bandgap and charge transport properties. This parameter change enables cost-effective manufacturing while maintaining adequate detection performance through optimized organic semiconductor layers and device architecture
2Measurement precision
If additional components like resistors and current sources are added to each column, then readout precision is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent merges the readout transistor with the pixel structure, eliminating the need for separate resistors and current sources in each column. The shared readout transistor approach reduces the number of components per pixel while maintaining readout precision through coordinated control of multiple pixels by fewer transistors
Solution Approach 2:
The readout transistor serves multiple functions: it acts as a switch for signal readout, provides amplification, and enables multiplexed reading of multiple pixels. This multi-functional design eliminates the need for dedicated resistors and current sources for each column, reducing manufacturing complexity and cost
3Ease of manufacture
If organic photodiodes are used, then manufacturing cost is reduced, but sensitivity and noise performance deteriorate
Solution Approach 1:
The patent employs composite material structures including organic semiconductor layers combined with appropriate electrodes and interface layers. The organic photodiode structure uses optimized combinations of organic materials with complementary properties (electron transport, hole transport, charge blocking) to achieve low noise and high sensitivity while maintaining cost-effective manufacturing
Solution Approach 2:
The patent optimizes specific regions of the organic photodiode structure to enhance local properties: charge blocking layers at interfaces to prevent carrier injection, optimized semiconductor layer thicknesses for maximum light absorption, and tailored electrode materials for improved charge collection. These local optimizations collectively improve sensitivity and noise performance
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 significantly reduces noise contributions and increases sensitivity, allowing for the use of organic photodiodes in x-ray detectors, enabling the detection of individual x-ray quanta at low doses and improving the signal-to-noise ratio, thus making organic photodiodes viable for commercial x-ray flat detectors.
Implementation Method 1
Photodiodes based on organic semiconductor materials allow pixeled flat detectors with high external quantum efficiencies (50 to 85%) to be produced in the visible range of the spectrum
Implementation Method 2
a pixeled flat detector having rows and columns of pixels, each comprise at least one organic photodiode, a reset transistor, an amplifying transistor and a read transistor
Data Source
AI summary
An organic pixel eel flat detector has increased sensitivity. This is obtained by a preamplification at the pixel level.