Monolithic Solar Cell Interconnection via Protruding Substrate Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional scribing processes for thin film solar cells induce defects in the active semiconducting layers and limit the spacing distance between sub-cells, resulting in reduced system performance and increased dead area.
Innovation Solution
The method involves using a substrate with protruding elements, depositing and scribing conducting layers, and employing chemical mechanical polishing (CMP) to separate sub-cells, reducing defects and dead area by minimizing the number of interfaces and optimizing layer separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional scribing processes are used to separate sub-cells, then mechanical separation is achieved, but defects are induced in the active semiconducting layers
Solution Approach 1:
The invention extracts the harmful scribing action from the active layer by performing separation only on the conducting layers. The active layer is completely avoided during the scribing process, eliminating defect induction while maintaining sub-cell separation functionality through gaps created in the conducting layers alone.
Solution Approach 2:
The invention segments the scribing process to affect only specific layers (conducting layers) while leaving the active layer intact. By creating gaps only in the conducting layers and not penetrating into the active layer, the method achieves layer-specific segmentation that protects the active layer from damage.
2Manufacturing precision
If conventional scribing processes are used to separate sub-cells, then sub-cell formation is achieved, but the spacing distance between sub-cells is limited, increasing dead area
Solution Approach 1:
The invention uses a template layer that is copied onto the substrate to define the pattern of gaps in the conducting layers. This template approach allows precise control over gap positioning and sizing, enabling optimization of spacing between sub-cells to minimize dead area while maintaining proper electrical separation.
Solution Approach 2:
The invention changes the parameters of the gap structure by controlling the size, shape, and distribution of gaps in the conducting layers. By adjusting these parameters through the template layer design, the dead area between sub-cells is minimized while maintaining effective electrical separation.
3Manufacturing precision
If multiple scribe operations are performed on conducting layers and active layer, then complete separation is achieved, but the number of interfaces increases
Solution Approach 1:
The invention extracts the separation function to only the conducting layers, eliminating the need to scribe the active layer. This extraction reduces the total number of scribe operations from multiple (affecting both conducting layers and active layer) to fewer operations (affecting only conducting layers), thereby reducing the number of interfaces.
Solution Approach 2:
The invention merges the separation function into the conducting layers alone, combining the roles of electrical conduction and mechanical separation into a single layer system. This merging eliminates the need for separate separation structures in the active layer, reducing overall device complexity.
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 enhances module voltage and current efficiency by reducing defects and dead area between sub-cells, improving the overall performance of thin film solar cells.
Implementation Method 1
employing chemical mechanical polishing (CMP) to separate sub-cells
Implementation Method 2
depositing and scribing conducting layers
Data Source
AI summary
A method for fabricating a solar cell includes providing a first substrate with at least one protruding element on the first substrate. The method removes a portion of a lower conducting layer located on the first substrate, wherein the removed portion of the lower conducting layer is located near the at least one protruding element. The method removes a first portion of an active layer located on the lower conducting layer. The method deposits an upper conducting layer on the active layer, wherein the conducting layer covers the at least one protruding element. The method removes a portion of the upper conducting layer, wherein the removed portion of the upper conducting is located near the at least one protruding element.