Organic Imaging Element Oxide Stack for Charge Transfer Stability
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Solution Overview
Problem
Current imaging elements face challenges in improving transfer characteristics and afterimage characteristics, particularly due to traps at interfaces between layers in semiconductor stacks and inferior film quality of composite oxide layers like IGZO, which affect high-speed charge transfer and heat resistance.
Innovation Solution
A semiconductor layer with a stacked structure is introduced, comprising a first layer formed using an oxide material with specific carrier concentration and bond dissociation energy, and a second layer formed using a second oxide material with a higher band gap and bond dissociation energy, reducing charge stagnation at interfaces and enhancing charge mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a semiconductor layer with stacked structure is introduced, then transfer characteristics are improved, but device complexity increases
Solution Approach 1:
The semiconductor layer is divided into multiple stacked layers with different oxide materials, where each layer has specific carrier concentration and bond dissociation energy characteristics. This segmentation allows optimization of charge transfer at each interface while maintaining overall device functionality, resolving the contradiction between improved transfer characteristics and increased structural complexity.
Solution Approach 2:
The patent employs composite oxide materials with specifically controlled carrier concentrations and bond dissociation energies in different layers. By combining materials with complementary properties (e.g., IGZO with specific carrier concentration ranges), the system achieves superior charge transfer characteristics while the material composition itself manages the complexity through predictable physical property relationships.
2Ease of manufacture
If composite oxide layers like IGZO are used, then manufacturing is simplified, but film quality deteriorates
Solution Approach 1:
The patent specifies precise parameter ranges for oxide materials including carrier concentration (1E19 cm−3 to 1E21 cm−3) and bond dissociation energy (3.58 eV to 5.50 eV). By controlling these physical parameters within defined ranges rather than requiring perfect stoichiometry, the system maintains high film quality while allowing flexibility in manufacturing processes, thus resolving the contradiction between ease of manufacture and manufacturing precision.
3Productivity
If charge transfer speed is increased, then productivity is improved, but afterimage characteristics worsen
Solution Approach 1:
Different layers in the semiconductor stack are assigned different local properties: some layers have higher carrier concentrations for fast charge transfer, while adjacent layers have optimized bond dissociation energies to prevent charge trapping. This local optimization allows high-speed transfer in charge-conduction regions while maintaining low afterimage characteristics in charge-blocking regions, resolving the productivity-reliability contradiction.
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 improves transfer characteristics and afterimage characteristics by minimizing traps and maintaining high film quality even at low temperatures, while also enhancing heat resistance and reducing kTC noise.
Implementation Method 1
a photoelectric conversion layer that is provided between the first electrode and second electrode, and the third electrode, and includes an organic material
Implementation Method 2
The first layer includes a first oxide material having a carrier concentration of 1E19 cm−3 or more and 1E21 cm−3 or less and bond dissociation energy of 3.58 eV or more and 5.50 eV or less
Data Source
AI summary
An imaging element according to an embodiment of the present disclosure includes: a first electrode and a second electrode that are disposed in parallel; a third electrode that is disposed to be opposed to the first electrode and the second electrode; a photoelectric conversion layer that is provided between the first electrode and second electrode, and the third electrode, and includes an organic material; and a semiconductor layer including a first layer and a second layer that are stacked in order from side of the first electrode and the second electrode between the first electrode and second electrode, and the photoelectric conversion layer. The first layer includes a first oxide material having a carrier concentration of 1E19 cm−3 or more and 1E21 cm−3 or less and bond dissociation energy of 3.58 eV or more and 5.50 eV or less, and the second layer includes the first oxide material and a second oxide material having a band gap of 4.5 eV or more and bond dissociation energy of 4.0 eV or more and 8.8 eV or less.