PECVD Device Edge Passivation via Plate Electrode Segmentation
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Solution Overview
Problem
Existing plasma-assisted vapor chemical deposition methods struggle to effectively passivate the edges of cut photovoltaic cells without compromising the reflectivity of the front surfaces, leading to reduced current and voltage output.
Innovation Solution
A plasma-enhanced chemical vapor deposition device is designed with a configuration that allows for deposition on the edges of stacked plates, using the plates themselves as electrodes to generate plasma only on the edges, thereby avoiding redeposition on the faces and enabling targeted passivation of the edges while maintaining the integrity of the front surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma deposition is performed on cut photovoltaic cells to passivate the flanks, then edge passivation is improved, but the front surface reflectivity is reduced due to redeposition
Solution Approach 1:
The patent segments the deposition process into two distinct stages: first depositing on the front surface, then rotating the substrate 90 degrees to deposit on the edges. This segmentation allows selective deposition on different surfaces without cross-contamination, resolving the contradiction between edge passivation and front surface reflectivity.
Solution Approach 2:
The patent introduces dynamic rotation of the substrate holder between deposition stages. By rotating the substrate 90 degrees between front surface and edge deposition, the system dynamically changes which surface is exposed to the plasma, preventing unwanted redeposition on the front surface while ensuring complete edge coverage.
2Stability of the object's composition
If conventional plasma deposition is used on substrates, then uniform coating is achieved, but edge passivation is insufficient after cell cutting
Solution Approach 1:
The patent uses dynamic rotation of the substrate during the deposition process to ensure all edges are exposed to the plasma. This rotational movement ensures uniform deposition on the edges while maintaining the ability to control front surface deposition, thus improving edge passivation without sacrificing coating uniformity.
Solution Approach 2:
The deposition process employs periodic rotation of the substrate, alternating between front surface exposure and edge exposure. This periodic action ensures that all surfaces receive appropriate deposition treatment at different time intervals, achieving both uniform coating and effective edge passivation.
3Productivity
If deposit is applied on one side and flanks simultaneously, then processing efficiency is improved, but front surface reflectivity is compromised
Solution Approach 1:
The patent segments the deposition process into separate stages for front surface and edge deposition. Although this requires additional rotation steps, each stage is optimized for its specific target, ensuring high-quality deposition without compromising front surface reflectivity. The segmented approach maintains productivity by efficiently utilizing the plasma source for each surface type.
Solution Approach 2:
The patent employs dynamic rotation to switch between front surface and edge exposure during deposition. This dynamic control allows the system to maintain high processing efficiency by continuously optimizing plasma exposure for the currently active surface, while preventing unwanted deposition on non-active surfaces through precise rotational positioning.
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 solution allows for efficient passivation of the edges of photovoltaic cells, enhancing current and voltage output by preventing unnecessary redeposition on the front surfaces, thus improving the performance of cut photovoltaic cells.
Implementation Method 1
plasma is created from one or more gases in it or applying an electric discharge excitation generated from radio frequency sources (40 kHz to 440 kHz)
Implementation Method 2
Chemical reactions take place after the formation of a plasma from gas
Implementation Method 3
a capacitive discharge excitation is performed by applying an AC or radio frequency current between two electrodes
Implementation Method 4
Plasma or PECVD vapor vapor chemical deposition (for plasma-enhanced chemical vapor deposition in Anglo-Saxon terminology) is a method used to deposit thin layers on a substrate from a gaseous state
Data Source
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AI summary
Plasma-assisted chemical vapor deposition device on plate edges, comprising a housing (2) having an opening, a door (6) configured to close the opening, gas supply means (8.1) and exhaust means (8.2) connected to the housing, an electrical generator (8), a suspension structure (S) of at least a first stack of several plates inside the housing, said structure (S) being configured so that the plates (P) are aligned with each other, a connection circuit of the first stack of plates to a terminal of the generator (8) so as to form a first electrode, the device comprising at least a second electrode (56) disposed opposite one face of the first stack and connected to the other terminal of the generator (8).