Transparent Electrode Layer for Organic Photodetection
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Solution Overview
Problem
The existing photodetection devices using organic photodiodes face challenges in achieving uniform film quality due to the need for inorganic protective layers during patterning, which are difficult to remove without damaging the underlying layers and can lead to residue issues affecting sensor performance.
Innovation Solution
A method involving the formation of a transparent electrode layer that overlaps with the organic photoelectric conversion layer and common line connecting portions, with specific etching techniques using CH4 and O2 gases to pattern the electrodes, allowing for improved patterning and reduced residue, thereby enhancing the quality of the photodetection device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an inorganic protective layer is provided on the organic layer during etching, then the organic layer can be etched with selectivity, but the protective layer is difficult to remove without damaging the underlying layers and can generate residue that deteriorates sensor characteristics
Solution Approach 1:
A transparent electrode layer is introduced as an intermediary between the organic photoelectric conversion layer and the etching process. This transparent electrode layer serves as the actual etching target, allowing selective removal of unwanted organic material while protecting the underlying foundation layer from damage and residue formation. The transparent electrode layer absorbs the mechanical stress of the etching process, preventing direct contact between the harsh etching environment and the sensitive organic layer.
2Ease of manufacture
If the protective layer is removed after etching, then the organic layer is exposed, but the foundation layer formed of the same material as the protective layer disappears at the same time
Solution Approach 1:
The patent segments the protective function into two distinct layers: the transparent electrode layer that is removed after etching, and the foundation layer that remains permanently. This segmentation allows the temporary protective function to be separated from the permanent structural function, enabling complete removal of the transparent electrode layer without affecting the foundation layer, thus maintaining layer integrity while simplifying the manufacturing process.
3Manufacturing precision
If dry etching is used to pattern the organic layer, then film uniformity is improved, but residue generation on the organic layer deteriorates sensor characteristics
Solution Approach 1:
The transparent electrode layer acts as an intermediary that protects the organic photoelectric conversion layer from direct exposure to the dry etching process. By positioning the transparent electrode layer between the etching plasma and the organic layer, the patent enables the use of aggressive dry etching conditions to achieve excellent film uniformity while the transparent electrode layer prevents residue generation on the organic layer, thus maintaining sensor characteristics.
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 approach facilitates better film uniformity and reduces sensor deterioration by minimizing the need for protective layer removal, leading to improved performance and reliability of the photodetection device.
Implementation Method 1
removing a part of the first transparent electrode layer that is not covered with the resist
Implementation Method 2
removing the resist and a part of the organic photoelectric conversion layer that is not covered with the first transparent electrode layer
Data Source
AI summary
A photodetection device includes a lower structure, one or more common line connecting portions and one or more pixel electrodes provided on the lower structure, an organic photoelectric conversion layer that is provided so as to overlap with the one or more pixel electrodes and not to overlap with the one or more common line connecting portions, and a transparent electrode layer that is provided so as to overlap with the organic photoelectric conversion layer and the one or more common line connecting portion, where a part of the transparent electrode layer that overlaps with the one or more pixel electrodes is thicker than other parts.